Rank Requirement for Solo/Team Arenas
I agree with your general argument. Just look at MOBA games where the matchmaking system makes two teams even by making sure each team has one beginner – you might end up with technically even teams, but you also end up with both teams trashing their noobs and often comparing out loud which one is worse in all-chat.
A level floor addresses this problem, but is only effective if the population is large enough. If the population of PvPers is too small or the distribution of ranks is too uneven then queue times could increase to the point where people start to drop out because they’re unwilling to wait. That in turn decreases the population further and soon you’re caught in a cycle that ends up with nobody PvPing.
You really need an algorithm that takes into account population, average wait time, specific wait time for each player in the queue, and maybe more variables I haven’t though of in addition to the rank of each player in the pool. It’s a hard problem and you only need to go play a few games of DotA/LoL/GW2 to see that it’s far from being solved.