Im not much surprised since i have been aware of this for quite some time. Premiere for XY series was lowest ever reaching barely 5.3. While previous series regularly reached around 9.5 whenever new saga was announced to begind. OS had over 10.0.
Ratings also took sharp decline in BW varying between 2.2 and 3.7 at some point which is pretty low for pokemon standards.
This could be one of reasons behind pokemon director Sutou Norihiko being replaced with Tesuo Yajima as main series organizer in Kalos, XY series.
But it doesnt help all that much with pokemon quickly losing interest among viewers, their loyalty and respect as evidenced in dropping oit of 10 most watched anime over there. Not once but several times already with another anime Yokai Watch produced by same studio which is responsible for production of pokemon anime OLM beating it in ratings and sales.
There are several factors to be considered such as TV becoming less predominant in this days and age among bigger variety of other anime on market which fight for people interest causing that pokemon drops in popularity. Pokemon episodes airing in time slot when kids are busy with their homework, activities etc.
Drop in natality happening in some countries.
Along with people growing up and losing interest.
However same argument can be applied to other anime out there as well. YET they are more successful and achieve much bigger ratings, positive reception and popularity than pokemon does.
WHY?
Because quality can definitely play massive difference in how many people are be willing to watch certain TV show and maintain their interest toward it with either negative or positive critic and impressions about it influencing how long series will be successful and attracting toward its watchers.
With that said based on what was most frequently talked about, complained and turned out to be controversial subjects over the years based on my observations and how often you could encounter negative word of mouth over it, its safe to conclude how following events contributed significantly in drop of ratings. As consequence of frustrated and upset people by direction in which pokemon series had been taken stopping to watch pokemon.
Such as:
Writer leaving Ash in repetitive loop stopping to evolve his character further keeping story in repetitive cycle without making any substantial growth out of it.
Very little care for continuity and more consistent storyline which along with protagonists should move things forward. Abandoned important plots(like GS ball, Team Pasma vs Team Rocket etc), repetitive start at every new saga etc.
Carelessly and without any hesitation replacing one after another important and heavily popular character leaving their stories, fears and struggles unresolved or ended up receiving half assed send of never being given chance to be used to half of their true abilities, let alone full potential.
Biggest backlash happened when Misty was replaced.
Pulling with itself at least 1/3(one third) of fans in USA, Europe etc quitting with pokemon forever once Misty was replaced in such sour and unsatisfying way. Because people loved her character and viewed her as huge part of pokemon series appeal losing lot of humor, identity, depth of emotions, healthy friction and variety of interactions once Misty left main cast with quality in that aspect for many decaying.
Accompanied with unfinished story, uncleared future and lot of potential left unused regarding water master dream, desire to live up to E4 Lorelei, her feelings fior Ash, her fears and conflicts in having trouble in using pokenmon to full potential or unexplored past about her family, prejudices etc.
No pun intended, but Misty leaving followed with May, Dawn etc being permanently written off resulted in significant portion of people quitting with pokemon series lacking brand, stable cast, fluid and continuity based story in paying respect to past, started plots, friendships with Ash and their own interest among direction under which they would unfold out.
To keep people intrigued.
This were NOT only reasons, but its worth mentioning they are one of them behind Pokemon anime starting with gradual decline with more and more people losing respect and appreciation for writers work.
Pokemon series with writers and directors questionable decisions and mistakes caused it to lose its credibility and popularity slowly, but very effectively over last 10 years.
Pokemon anime simply doesn't do enough to make those new viewers more attracted toward this show than other ones available on market such as Yokai Watch, Detective Connan, Fairy Tail, Doraemon, One Piece, Inazuma Eleven Go and many others.With less kids being willing to choose pokemon over other anime out there and follow it.
It does even less to broad interest to wider group of potential viewers and customers(this case older fans)who would get their interest sparked in wanting to revisit their childhood memories and spend cash from their hard earned money on new products falling under pokemon fever once again
Something which could easily be achieved increasing hype, older fans interest and new kids curiosity for pokemon series if older highly iconic and popular characters were brought back.
Making new kids curious to find out who are this people. From where they know Ash and better understand pokemon history showing them how pokemon is in reality one big story which builds on itself. With Ash collecting experience and gradually maturing over time .Something which is anything but true with current resets and forgetting about past like it doesnt exist.
At same time through positive word of mouth and good reception many of older fans who no longer watch pokemon might be interested in coming back to revive on their childhood memories through recognizable characters. Making them excited to see those who were part of their childhood being brought back to life seeing how much they changed and in what new adventures writers are planning to take them.
Because many of older fans would start watching again instantly if :
-older companions they like were to return,
- if writers provided some sense of direction taking Ash on next step reaching new heights as trainer such as winning league showing what else he needs to accomplish to become pokemon master. Show him deal with pressure of fame and high expectations in case of winning finally regional league. Show what other steps beside winning champion league there needs to be accomplished to acclaim master title. Bring back his father bringing much needed substance and deeper growth to his character etc.
- Less repetition and more original storylines increasing on world building, continuity and previous lands Ash and friends traveled through, development and experiences along with various previous characters not being buried in past. But acknowledging their importance and remaining relevant to pokemon universe.
Having more consistent and on going story which builds on what was established before.
Something which well cannot happen when you constantly reset everything leaving just Ash as part of equation.