You won't get any arguments from me RE Master Loot. Our resto shammy respecced to Enhancement for a farm Ashvane kill, forgot to change his loot spec and got a 450 socketed Coral that he couldn't trade. I'm still stuck with a 415 socketed one. That was one big feelsbad moment.
RE Corruption, at least you can get it via other means. I got lucky and had a rank 3 Infinite Stars from a WQ emmisary reward. A buddy got rank 2 TD on a M+0 ring when he carried a guildy's alt. The weekly cache gave me rank 2 Void Ritual which I'll use as soon as my corruption budget allows, and in M+. The sheer number of potential sources dampen the RNG quite a bit. But of course you'll still have haves and have-nots.