Yeah, you're right, but it also roughly seems to follow the popularity of the beings themselves... people go gaga for dragons, they tend to like wolverines or at least mammals that have that sort of head/body shape, Blaziken is a ninja but it's still a rooster, Infernape is a... well, ape, and it seems that people either love or hate them. And pigs are just generally unpopular animals. Of course, like I said, this is really broad and kind of spotty, but it's just an observation. Based on this, I'd say Fennekin is going to be a very popular little fox!
EDIT: Of course, nostalgia plays a big part! But I genuinely think that people would still find Charizard/Typhlosion more appealing than Emboar/Infernape if they had swapped generations. But that's just what I think.