Stop the WoWificaton (ui mods)

[ItMe]

What does this mod actually do that gives you an advantage?
What does this mod do that could lead to something like this:

But the more people who use them, the more people expect others to use them and it becomes a gatekeeping issue to progress in high end content. I know it for a fact, I've seen it in other games and it's already becoming a problem that will only grow. Don't use damage meters? No invite. Don't use addons to automark things? No invite.

I've only skimmed some of the 12 pages in this thread, so forgive me if this was answered.