Firstly, LD is not a bad skill. You and your team plan out when you are going to use it and there's no problems, which is what you should be doing anyway. Learn to communicate. There's no point discussing it's merits outside of raiding, because it literally doesn't matter. Casual content is casual content, you die, so what.

Secondly, on the arguments about MT and OT, what's the point in that discussion? Every combination of tanks can work well in both roles, and it only matters who does what if you are speed running.