No, I don't agree people shouldn't be able to use pseudonyms. Years ago, I reacted to something Michael wrote using my full name. Now, that one reaction regularly pops up when I google my name. I don't like it. Not because I didn't mean what I said or regret saying it. No, mainly because that comment and some others on other photography sites show up amid or above google hits that pertain to my profession, journalism. When people google my full name, I want them to find me as the journalist first, photographer second.
This goes further than that, since I also do model photography and used to travel in the Middle East, where that wouldn't go over well. Even more reason to use an alias.