I think it would be a good idea in theory, but I don't know if I'd actually play it. Back in my earlier ROM hacking days, before I got a flashcart, I would be forced to play in on the computer and exclusively on the computer. This was okay, but I recall never getting much time to play it because I was always either A. Outside of the house doing something else (such as work or school or in the car for three hour rides to family member's houses) or B. On the computer but doing something else (such as homework).
When I play Pokemon, I like having it on a handheld because of that portability. It means that I can play it whenever I want and where ever I want. I usually end up playing Pokemon during long waiting times, which 95% of the time for me are away from the computer and are in a location where wifi is spotty (such as in the car on the highway) so even a laptop wouldn't cut it for me.
I've heard various theories as to why certain people think there won't be true Pokemon games for PCs, which range from PCs being more costly to maintain than handheld systems to potentially alienating the target audience (most likely children) by having to deal with things like COPPA if the game is online. I'm no expert on PC gaming, so I can't speak for the legitimacy of every single theory, but I do think this is an example of an idea that sounds great in theory but would be very difficult to implement right in practice.