It sounds like the issue may be a sybil attack. Those can be mitigated with introduction of a cost.
The cost does not have to be a spend. It could be a combination of proof of stake with a probation period after a proposal is submitted. That way, proposers will know they only have 1 proposal per X period (e.g., 1 month, 3 months, etc.) so they better make it count.
You could introduce further controls like require a higher minimum level of proof of stake before being able to submit a proposal to snapshot, have a probation list for wallets that are known to submit garbage or trashy proposals (removal from the probation list may be possible with some form of petition and DAO vote, etc.), and other strategies. Basically, implement internal governance and controls specific to snapshot proposals.
The reason I say all that is I'm a little hesitant to say it makes sense for the (obviously very hard working and busy) DAO core team to make blanket rejections of proposals. It just feels un-democratic, may result in disenfranchisement for the community, is ripe for possible corruption, and there are alternatives (like introduction of controls to mitigate sybil attacks against our governance mechanisms).
Much appreciation to the team. Really. I am so grateful for all you do.
For now, since I know implementation of snapshot controls requires resources and wouldn't be a priority, I would be in agreement for blanket rejection of proposals that don't first vet on the forum. I just would like to see more automated snapshot controls to mitigate sybil attacks in the future.