When vine ran up against a similar issue they registered the .co tld and it hasn't held them back. Plus, .co's are selling for around $10 still for decent names. This might be a good area to look at.
A lot of developers are so because of the need to fix problems, that and a flair for logical mathematics. Sitting on a beach sounds nice but I think it would only be a matter of time before members of this community try to come up with a solution to sitting on the beach.
I think workers work. The satisfaction is in achievement of worth, or at least in the endeavor.
There's also the issue of "does the username belong to the user". So if user a deletes their comment and user b quotes them both by comment and name, should user a's name be masked when they delete said post? Well, isn't that user b's content that's now being infringed upon? The current non-delete mode is fine - just don't write stuff you don't want on the web on a forum, and if you do then update with a new comment retracting the statement.