Graham, overpopularity can kill a site quite easily, I should think, particularly if a percentage of unchecked (in both senses) errors are included. What is your stance on faulty health advice? Legal information? How about, as in this case, character assassination?
Just because there is as yet no culpable entity on websites, it does not follow that that case will always apply, and IMO haste-the-day when there is one.

On your point that Wikipedia (Wikipaedia?) cannot (sensibly) cope with their growth, then it follows that in a short while they will not be able to cope with the required corrections, either. A general encyclopaedia is the biggest single source of information that scholarship compiles, but if it is not compiled by named scholars, but by unknown people with unknown agendas, then sooner or later someone's head will be on the block, and probably not the guilty party's.

No, I don't feel constrained to support them financially. I do think they might be better advised to specialise, like Mudcat does. How unwieldy would the DT be if it included every piece of music that was ever written?