I agree with you, but do you honestly want 600+ Pokemon? They can keep making new ones while keeping the number relatively small.
Also, forgot to post my reason for why a GSC remake is so important. IMO, to this day, GSC is still the best generation for a number of reasons. The number of Pokemon was just right, there were plenty of little but nice things (Mystery gift, decorating your room, catching contest, radio, making your own pokeballs,etc.), the time and date was actually used for something other than catching different pokemon during the day/night, and the big ones, you could revisit the old region, fight the Kanto gym leaders including a now gym leader Blue/Green and different leaders, and fight Red in an epic battle.