When I read "X is great" while using Y, I reflexively put my choice under scrutiny. I see that as the main reason to talk about technologies X or Y at all. And

When I read "X is great" while using Y, I reflexively put my choice under scrutiny. I see that as the main reason to talk about technologies X or Y at all. And if X has some terrible drawback, network effects can make it worthwhile for me to dissuade other people. Hg vs. git isn't a compelling example, but if I want to never face another svn-induced merge conflict again, I myself am actually better off if everyone I may collaborate with already knows how troublesome that tool is (I would have said "nightmarish" in the svnmerge.py days).