People do not understand elite spec idea
I think the complaint more has to do with the fact offhands give the absolute least amount of skills possible when adding new weapons, so they (feel like they) get less new skills added. Furthermore, offhands typically have longer cooldown, less used abilities, which means a new offhand is a lot less game changing than a new mainhand or 2h would be. You won’t get new builds from a new offhand as long as these two points hold water, you just get modified old builds.
(this is purely focusing on the weapons, as the op was focusing on it. Yes there is more than weapons being added.)