Those people are essentially asking for someone to facilitate the transaction for them. We already have that, in the form of online auctionhouses like eBay and open market storefronts like Amazon. Want to buy a used tv without interacting with someone you don't know? Amazon or eBay are your best option.

I'll admit this doesn't really work for big stuff like couches and other furniture, but in that case you're asking for hyperlocal protections that an online business just can't offer. Check out a thrift store, pawn shop, estate sale, or local auctionhouse instead.

Craigslist has it's niche, and it's niche doesn't really have room to improve.