Yeah, it would be inaccessible without platform subscription, like any other multiplayer game. Most console players I know are already paying for it anyway.It would be inaccessible to console players without premium platform access - as they can only play in Solo. While it would remain accessible, in the same way that Open is, to PC players, it would very likely be unpalatable to those players who don't find PvP to be "fun" - in which case they'd probably not bother with it either.
All players would benefit from Open Only, even those who don't PVP. If you want to know how this is possible, give the OP another read. I know the author of this post and he doesn't PVP at all.The issue at hand is that all players bought access to Powerplay and can currently engage in it any game mode - and only some players would benefit from PvP-gating it to Open.