i dunno if this has been talked about, dual spec was introduced in wotlk, it allows ppl to switch between 2 specs(or more correctly between 2 different talent builds) without spending gold, without traveling to their class trainer, it is a huge QOL change but it doesnt have any impact on performance it doesnt change the game in a radical way it just makes life so much better for everyone, ppl who want to pvp and pve, healers and tanks that wanna have a dps spec for farming/questing/dungeons, etc.
the game becomes so much better and fun, i am a no change person but dual spec is just so good, it would increase player participation, there will be ppl who will not have gold to respec to go into pvp even if they want to, imagine a prot warrior he wants to pvp as arms aswell but he doesnt have the gold to respec everytime he wants to pvp so he just gives up, thats a loss for the community ,for the game, and there wil be a ton of ppl in this situation.