Personal loot in Legion has it's benefits. They finally fixed one of the main problems with you being finally able to share the personal loot you got but there is still the chance of nobody getting anything. At least with master loot you get guaranteed loot, which is especially helpfull in the early expac pugging.
If I were to lead a PuG I wouldn't want to do it without being guaranteed the loot I want to have - if it drops, that is. People doing the extra work of organizing a PuG have the right to reserve items they want. If people are not happy with that they are free to create their own raids, that's how I did it. The funny thing is that after a certain amount of time I was finally able to understand why those raid leaders used master loot.
Re: "still the chance of nobody getting anything" - sadly this reply probably doesn't get noticed at this point in the thread, but that isn't accurate. As of 6.2, Personal Loot drops a guaranteed number of items just like Group Loot does. If you have a ~20 player raid, you'll always see 4-5 drops from every raid boss, just like with Master. And there's the advantage that you'll never see a completely useless drop (e.g. a bow if you have zero hunters).
Watcher
Re: "still the chance of nobody getting anything" - sadly this reply probably doesn't get noticed at this point in the thread, but that isn't accurate. As of 6.2, Personal Loot drops a guaranteed number of items just like Group Loot does. If you have a ~20 player raid, you'll always see 4-5 drops from every raid boss, just like with Master. And there's the advantage that you'll never see a completely useless drop (e.g. a bow if you have zero hunters).