Everyone is entitled to their own opinions, but not their own facts. The facts say you're wrong and gen 1 is awesome.
*now that I have that nostalgic outburst out of the way*
Two main points, both centred around the need to place generation 1 in context, and not judge it based on the standards of today:
1. As obvious an idea as Pokemon seem now, it wasn't back then. They'd have been subject to resource constraints, timelines, limited technology and the need to deliver a minimum viable product in a way they just are not these days (due to the massive sales any mainline Pokemon game can expect and the more powerful consoles)
2. In the early days, the whole allure of the project was our ability to place ourselves in Pokemon's world. Hence the need for a multitude of believable, relatable Pokemon that look like they might fit in to our lives. Remember this was in concert with the (then) hugely popular TV show and playing cards. It was all designed to draw kids in. With a built in audience we've been able to move away from that a bit.
starcraft - Playing Games = FUN, Talking about Games = SERIOUS