Dude. Before the Physical/Special split, all Fire, Ice, Grass, Dragon, Electric, Water, Psychic and Dark type moves relied on Special Attack.
This means the elemental punches were all Special, so a strong Special Attacker was better with those punches than any fighting type. For example, Alakazam.
After the split, this shit completely changed. The way many Pokemon were used was shook up, you can't use elemental punches on Alakazam effectively because its Attack stat sucks.
Pokemon of any type could be geared toward either Physical or Special and still be great, instead of limited to what their Type was classified as. It completely changed the metagame, and how many Pokemon are used.