It was all about making the world better again...
If I ever come up with a mind blowing idea to free human race and the plan is to give it away to anyone interested I wouldn't HODL all the other TLDs just for the sake of it. Where is the decentralization if I own them all ? .Practice what you preach I guess...
If it was meant for business I think they are going to buy all the extensions needed for them to not get attacked by phishing sites. Or maybe the cryptographers are not just into webmaster's and domain business. They are coders and close to being geeks which at the beginning may have little idea about the economic effect of Bitcoin. All they want is to have some board to discuss on which is documented online.
Bookmarking works better. Bitcointalk.org I believe was hacked before, I'm probably not around yet but they do recommend resetting passwords every now and then.