I have to disagree
They're animators and writers, not brown nosers. You have to take into consideration the plot and the actual animation that works out with the plot. It's not a simple task. It takes a lot of work to make an animation, even with the right tools and also figure out how to formulate it so the pacing is kept up with a mixture of both the action and the small story that goes with it so it ends every episode with some sort of conclusion to the current conflict as to not leave the viewers hanging. All the writers, Music composers, animaters, voice actors, and the rest of the cast need to plan all this out in order to make a good series.
Example:
If they give interaction like "X Character won the battle against the Y Pokemon" what will he do next episode, YOU THE VIEWERS DECIDE FOR THE NEXT EPISODE!
Will he
-Catch it
-Kill it
-Let it go
The polls will take some time to go through first of all, and second, all the plans for the future episodes will be completely altered. They wouldn't have the time to do all the planning, animating, and writing for next week and will make it look rushed and lazy. Not only that, the option might also change the pacing of how many episodes their are. For example if the Pokemon Y was captured or was freed, it might have a conflict for a later episode turning it into an entire episode therefore not planning out the route of the main character and his overall pacing with the region.
The short: though it sounds like a good idea in the perspective of the viewers. You have to take into consideration of how much effort it would take and the near impossible planning that would be involved.