You will only usually see it on TC HM and Xeno, possibly other HM's if it is pugged but it is usually rare to see since a 55 HM op being pugged is usually a recipe for disaster. I have no problem with it as long as loot rules are laid out ahead of time and everything stays on the up and up. Usually you can tell when something is a little shady when all of a sudden somebodies health drops because they swapped out accordingly or somebody types in their roll but that is usually an issue with somebody in the group being shady not the lead, and that can happen either way honestly, but I do think it is the fairest way to do things sometimes.
The HM's I can understand, but the TC one was Storymode. I understand how it can be used for good, but it can also be used for bad, and I guess.... more than anything ... I was curious if it was worth it to wait it out and see ... I did, and it worked out ... but one cannot expect EVERY ML to go smoothly or fairly.