Pokemon isn't bad, it's actually quite good. I loved playing it as a kid. The only problem is that ironically and puntastically, the series has never once evolved. Playing Red, Blue, and Yellow were quite a lot of fun, so the developer copying the same formula with different maps and new Pokemon in Gold and Silver was a great idea. However, after that stellar success, they somehow fell into Nintendo's unfortunate playbook of just remaking the same game every few years and it being a guaranteed success. Where is the innovation?
Let's go through a short track of games that actually tried to do something new with the franchise. The biggest ones were early titles like Stadium and Snap. I regard Stadium as being one of the most fun Pokemon games ever, and Snap to being a pretty original and very fun title, even if it wouldn't last you very long. But after the success of these games, suddenly they decided that they could just clone the more successful of the two every few years, putting them in the same trap as before. The major issue though is that Stadium 1 and 2 have been the only ones that seem to have put any real effort forward into making an enjoyable game, the rest are just sort of okay. The only stadium clone I consider worth any salt is XD, and that's because it has a very interesting story mode. It's interesting not because it's really all the good, but because it takes some risks and doesn't follow the same idiotic pathway as the gameboy games.
Now let's look at the simplistic plot of Pokemon games (and before you say anything, I am looking too deeply into this). You start as a child of a single parent. Upon discovering your first Pokemon and being given one by a Professor, you then go on your way to collect more. However this soon turns into a strange narcissistic quest for power. You have to become the very best, and you will kick the ass of any person that stands in your way. Eventually you will rise to the very top, but there is no resolution, the game isn't over. In fact, it isn't over until you put every beast ever created in captivity and stored conveniently on your hard drive. Man, I never knew I could be so cruel.
Anyway, all of that was definitely too long winded to be of any real value to this conversation since this is just a shoutout to current fans, but the TL;DR version would be that it wouldn't kill the company to come up with a game that didn't have the same plot as all of the others.
