At goonsaloon, spam is free speech, including spam that wipes the board clean. Anyone can post anything, and anyone can erase all of everyone else's posts. Goonsaloon is an expression of its admin's views about free speech and the transitory nature of some imageboards and other philosophical and artsy things that come to mind if I sit and think about it too much, which I do. Good on ya, goon admin!
From a practical standpoint, it also means that anything posted there might be seen by only one or two people, or possibly even not at all before it gets wiped. Sometimes I like very much the idea of doing the virtual equivalent of putting something in a bottle and tossing it off a bridge, but sometimes not. The transitory nature of 4chan's /b/ with its 15-minute lifetimes was the first place I'd ever seen that, and I liked both how it worked, and the fact that it was illusory, since anything posted there was simultaneously archived forever by entities unknown.
It is because of that illusory aspect of impermanence on anything related to image boards that I think they need onion addresses. Clearnet chans are far more subject to correlation attacks to identify their users. The relevance of this has increased significantly recently, with all the government attention being paid to who is posting what.
