Permanent URF

With how massively popular URF is, shouldn't it be more than just a "yearly tradition". Among all of the game modes that get cycled this one (in my experience) is the one that draws the most players, and sometimes, brings players back to the game temporarily. I understand that it's "unbalanced" but that's not a viable reason to trash it because there's numerous updates to normal matchmaking to "balance" characters. Why not just make it permanent?