Pokemon's problems aren't the core mechanics, they're super simplistic and sluggish as all hell and the games aren't very challenging but none of that is the problem really making it rough to play.
The problem is what an awful void of nothing the entire scenario is. There's so very many things they could do to make it an interesting adventure, but they dont even lift a finger to try.
The original Dragon Quest, we're talking the 1986 one, the godfather of the Japanese RPG, has arguably better dungeon and scenario design than the last Pokemon I played, Pearl I think. If the scenario was fun and amusing, it might hold my interest in spite of the skeleton systems, but sadly it never really made any leap.
But then again would you risk botching up your cash cow?
I think if you grew up with it and like the little universe and designs they got going, you might keep playing it, if you need more than that, you probably wont. Pokemon games are pretty child centric bus stop trade/collect titles, and I doubt they'll ever feel the need to change that. It's not like the world will suddenly stop producing kids who like to collect shit.
I certainly wore out my Blue cartridge when I was younger.