Tanks could be OPAF and hella fun to to play and they would still be the least picked and DPS would still be the most picked.
Could Blizzard do more to make tanking more attractive? Sure.
Can Blizzard solve the DPS to tanking ratio with balance changes? No. Never.
There is only one real solution to the problem, and, well, no-one is going to like it. At least I don’t think so.