It should've been ditched after Yellow oronce G/S/C introduced Dark and Steel types shuffling the balance all over again.
Water: 2 Weaknesses 4 Resistances
Fire: 3 weaknesses 5 Resistances
Grass: 5 Weaknesses 4 resistances
There's no balance between the 3 other than a rock-paper-scissors scenario. Not to mention the fact that having a fire starter usually gives a pretty good advantage to any player, especially when there aren't a lot of fire types in any game.
Dual typing was a great move. Swampert lost it's weakness to Electric. Venusaur isn't weak to Poison. The fire/Fighting types were no longer weak to rock. However Empoleon became weak to both ground and fighting, the second types of the other Gen IV starters.
I think it's long overdue for a change. I'm not saying do the fighting/dark/psychic trinity but toss things up. I'm tired of the old formula. Give us a well designed Pokemon with a good move pool and doesn't pit you against your rival/s every time whom has a type advantage.
Why not bug/psychic/ghost? Poison/Steel/Rock? Fighting/Electric/Ice?
The reason they use Fire Grass Water isn't because those types are perfectly equal or anything like that.
Its because they're all weak to one of the three, resistant to the other, and perhaps more importantly its an easy-to-remember set of weaknesses / resists. Fire being weak to Water makes perfect sense and is very easy for new players to remember. Same with the others, they all make sense and are pretty typical and simple weaknesses that new players will easily grasp.
~ Master of Electricity ~ Electro: 0518-6613-7620 - Pokemon White