the current system looks insuficient to me
Yes, it is. That's the whole point of the post: the changes to the site are not forthcoming, so we had to develop these rules to work within our existing infrastructure.
No collab accounts. We feel that these will ultimately create more problems than they solve.
I still don't get what the problems are... Collab accounts seem far more user-friendly.
No solution is going to be perfect while we lack the proper infrastructure. Collab accounts were rejected primarily for the same fairly obvious reasons that multiple accounts are ubiquitously prohibited everywhere: sock puppets, ballot stuffing, spamming, etc. It also seems hackish and impractical for every combination of two or more pixel artists to create a new account when they want to submit something. It puts a large moderation burden on us and creates opportunities for exploitation.