The fact you need to do stuff with it makes it seem... y'know... well, childish. You'd need to pay attention to it and grab things. So either you can walk around in circles in your own home waiting for something interesting to happen or walk around town and randomly take out your toy Pokeball and start fiddling with it in public.
Each to their own. I kinda liked the Pocket Pikachu for the same reasons you mentioned, johnny. Only now it's got more uses(you can even play minigames to get free items for the main game, like how Watts can be traded in for stuff in Gold/Silver). A walking Day Care sounds nice if you've already maxed out your Pokemon's EVs and are waiting for it to get to Lv100.
(Remember there used to be a topic? Good times, good times.)
YAY GROUDON I've never had a Groudon before and I'm pretty hyped I get one now. And also new Elm art, which is awesome, 'cause he's all panicky, and that's why he's my favorite professor.