Not to OP but some other posts in this thread about combos:

If they'd ever consider putting combos into 1 button, it should be optional imo. Having multiple combo buttons makes it easier for me to manage and map abilities in my rotation in a way that makes more sense to the mind scheme, so it's more convenient for me to have them on multiple buttons instead of 1.

In PVP it doesn't really matter since it's all about berserking and burst there so it sort of makes sense to have them on 1 button.