But how would he learn how easy it is to get other's usernames without actually taking it? He has to run through the whole process at least once to be sure that the process he would share with us works or not.
If you read the whole post, at a few websites he had to email their support, asking for transfer of their usernames. Once they agreed to give in 'next 48 hours', he could have finally said, "No thanks, I just wanted to test how easy it is." You just need the will. I bet all this sharing of info was an after thought.