If you weren't old enough to play it the first time, they'll be hard to get into. The games are incredibly unbalanced, bland, and slow. They don't feature any modern luxuries like running, auto-sorting items, re-usable TMs, reasonable-acting-AI, etc.

If you want the original experience, the games are there, but I don't think you can get an authentic experience. Finding MissingNo for the first time or talking about the game with friends in school made the experience, but you don't find this on the cartridge.

People who ONLY recognize the existence of Gen I probably haven't played the new Pokemon games much, or they were casual smurfscrubs in the first place. I can't vouch for the Pokemon design starting from Gen II and on, but many of the Pokemon they added were at least interesting, if not competitively viable. We can complain about how much the art design sucks now, but that's not going to help.

The original 190 (yes, 150 fully complete Pokemon, 1 scrambled in at the last second, and about 40 that correspond to non-junk data) were all based on Japanese mythology, so the Pokemon felt real or familiar.

I personally have not played FireRed, or LeafGreen. By the time I got back into Pokemon, it was already the end of Gen III; I beat RSE, but then I moved onto the Gen II remakes, and skipped PPD. In comparison, I have not played any of the remakes of the FF games. I ran an emulator for each one.