Can the ARAM format be changed already?

Personally, playing ARAM is the most fun part about this game as I've gotten burnt out from playing ranked, but it feels like I'm being punished for playing it too much. What I mean by that is that I'm matched with all ARAM accounts now. I see the same OP ARAM champs in every single game I play and games are so stompy. I'm fine with losing ARAMs because sometimes it's not under our control, since it is supposed to be "all random", but it's not random. It's a bunch of accounts, with OP champs on there, who get a pick of the litter of an abusive champ in ARAM. So, why can't every champion be unlocked, and have "All Random, All Mid" be truly random? Am I missing something here? I'm fed up with it at this point and cannot see how the negatives of this be worse than what ARAM is now.

Edit: I've read all your comments and I appreciate the discussion going on here. Unlocking all of the champions may be a little too drastic, or maybe not, but I personally like the idea. In the end, I do think there needs to be some sort of change, whether or not my proposed idea is that change. Some people are worried about getting champs they're unfamiliar with, but isn't it just as likely that the enemy team will get champions they're unfamiliar with too? I personally think it's okay if, in some games, you get an unfamiliar champ because at least it's TRUELY RANDOM. Bite the bullet and move on. That's just my two cents; Keep this going so hopefully someone from Riot can reply on this topic :)