shocka, I can definitely assure you that casting IS a limited resource and there's no hatred or conspiracy against the other divisions. If you want to criticize invite, casting is not it.
From what I've heard both Plat and harb are very busy people (I'm pretty sure harb has both a job and school), and I know personally from having that kind of schedule that doing regular reviews is pretty difficult not to mention really taxing mentally (I've tried). At least they're trying to do SOMETHING about bringing up numbers for Open. From hanging out with them at LAN (and this goes for literally every invite team and any player I've met, which is the majority from seasons 13-15), they've always been nice and encouraging to lower level players (there's a good reason that there have been more and more spectators coming to LAN even though it's not normally a spectator event...).
I think you're drawing something they probably said offhand a bit too much out of context.