Gnutellafan, logik says: if Xolox is bad block it, if Xolox is not bad don't block it. Question is how bad is Xolox, please give technical reasons no emotional. Blocking without reason makes no sense, that's censorship. "Old" doesn't mean bad automatically, perhaps it just means nice with less features, perhaps.

Speaking about Xolox it was one of the best client of it's time, pushing Gnutella and development forward! Some client, e.g. Bearshare still haven't gained the same functionality (in this context Bearshare looks still old, should we block Bearshare now?). When you doubt, let's list technical advantages and disadvantages. I have analysed Bearshare and Xolox a while.

Comparing some of the most favourite clients, Limewire, Xolox, Limewire, Phex, Bearshare....
Bearshare is those with less functionality, less technology, the oldest in this context!
In your words: Oh well, KILL IT!? :-)