Clearly you need to nickname your Pikachu something to do with irrigation or corn
Oh, it's totally shonky. Narratively, the infrastructure of the game doesn't gel with the traditional pokemon experience, where each individual creature becomes special to you as you train and give it personal skills and abilities. The pokemon in PG are pretty faceless, especially since you need to amass a ton of them to evolve something to its final form, and can't affect what skills they know or even use them in the wild. That paired with the technical crashes and heavy-handed microtransactions doesn't really spell fantastic game.
But! The physicality of accurately gauging a pokemon's distance and deftly flicking a pokeball at it is so satisfying in a bite-sized, easily repeatable way. And the collectability of it, seeing all the empty spaces in the pokedex getting filled in (even though you already know what the empty spaces are). I'm much less interested in the gym battles, but as of right now the only way to earn pokecoins without paying real money is to be holding positions at gyms, so there's that.
But yes, despite all the issues, the franchise and the conceit are charming enough that people are super-excited to see a sad red fish flopping around on the sidewalk, haha.
(Has anyone caught any magikarp yet? Apparently you need 400 karp candy to evolve a Gyrados. Daunting!)
Some quick googling shows PG at 7.5 million downloads in America two days ago, about 5 days after launch. Angry Birds and all its sequels sit at around 3 billion downloads worldwide, so there's some catching up to do! We'll have to check in after more international releases.