I still watch it because:
-I like the battles that do not involve Rokketto-Dan. Some are lackluster but some excite me more than any other anime ever did.
-It's the only anime I have patience to watch that isn't bombarded by fanservice for yaoi/yuri/ecchi lovers since it's aimed for children.
-It makes the world of the series interesting. I like the game but the world, towns, environments, etc, are pretty boring.
-Since Satoshi has been doing slightly better in the leagues I'm still hoping he will keep improving on them. (I actually like how he makes mistakes we wouldn't.)
-I like seeing Satoshi and the other characters getting closer to the their goals, wether or not they actually achieve them.
-Up to where I'm watching it feels like the writers are getting better. I'm expecting it to to continue that way.
-Some episodes are hilarious, and they don't resort to blood, swear-words, nonsensical nerdy humor to be funny.
-It gives me a better impression on pokémon I would be disliking. (I used to think achamo was awful. Watching the anime made me like him.)
-I'm watching in japanese, with no subtitles. So it helps me improve too.
Those are the reasons I can think of.