The grind wall is an utter fabrication, you can do any activity you want after a couple of hours of 'grind' ie learning how the game works.
There really is one for PvP though! And it's not fabricated by that particular player wanting to get into PvP but by the other PvPers who've set the meta at a certain level.
Complaints should be directed at them, or indeed re-directed and made into reasons for a separate PvP game-mode where any loadout can be selected from a menu with no grind. Which would be fine but utterly trashes the intended slow upgrade path of the PvE game that everything is built around, thus not compatible with the rest of the game.
I really think the PvP community would be wise to get behind my vague Elite: Crucible plans - it gives them absolutely everything they want apart from being linked with the main galaxy. I would argue that the loss of solo/pg players 'messing' with their stuff and loss of grindwall would be a worthwhile exchange