Like many social or networking platforms especially in startups, you get back what you make of it.
There is a such a spectrum of ideas and approaches that you're unlikely to get a better product out of confining people to any category or stage. Personally I think its a great platform if you put your VC hat on (you're contributing effort rather than capital). If you don't find a the right idea or person to work with then you'll likely learn a lot from seeing what everyone else is doing and how they are thinking (positive or otherwise).
All the big VCs do periodic posts but it takes a bit more work to find the truly novel ideas and projects. With YC co-founder matching, you start with a varied pool of people who have set out to be founders - its up to you what you do with that.
The exact same thing thing happened to me last night. Account suspended with a perfect but low volume selling record. I haven't used it for a year.
Received an email this morning saying it has been reinstated. Either way it did make me waste my time removing my cards from PayPal and emptying that account. The reason I stopped using them is that they appeared to manually use the direct debit to take money from my account (and more than they should have) after I'd logically won against a fraudulent return according to their policies last year.
My last action was to make a SAR which showed again that it was closed against their policies.
Knowing eBay at first I thought they may have looked into the case and wanted to cover their backs. I wouldn't be too surprised now if it was just a bug.