But such thinking can block innovation. It's a form of path lock-in. Both UNIX and Windows "gurus" are guilty of this, of seeing their way as the "one true way". Just because it's always been that way.
New ideas are not always better, but sometimes they might be. In the longer run "I'm used to this" (on its own) is not a good argument as there will always be new people that are not used to your specific blub, and if they can be more productive or make more reliable/secure systems then eventually you'll be out of the market.