It's not as bad as it has been in the past, but I do sometimes feel like DIR divers look down on me for not being a DIR certified diver. I know they don't like how I dive sidemount and sometimes solo, and while I agree that there is value in standardization and teams, I can't fit in some of the caves I dive in backmount, and sometimes it's safer to be alone.
I have never had any of them actually tell me I'm a terrible diver for not having a GUE certification. I have only gotten the feeling. I know several DIR divers, and while we have a friendly banter going on much of the time, I feel that they do respect me decently, but would respect me more if I had a Fundies or GUE Cave certifications.
I think the most important thing is to be able to explain why you dive like you do, and I do feel that many DIR divers are able to do so, which is awesome. I enjoy having debates about various methods of doing things with those DIR friends of mine.
A lot of times, people come across differently online than they do in person. It's impossible to hear vocal tone or see facial expressions of a poster while they post. I think that fact fuels the "two sides" feeling, even when people might not seem so segregated in person. Most of the DIR divers I know are great people, as are most of the non DIR divers.
I've had an SDI instructor try to tell me that a friend couldn't take OW in a backplate and wing with long hose. He made her donate the bungeed backup for the OOA drill...needless to say, that didn't work too well. He was a newer instructor, and I have been told by other SDI instructors that students may use a backplate and wing in class, as well as a long hose configuration. I think the bigger issue was an instructor who had never seen a backplate and wing before.
We can't forget about Jeff Hancock and his Hancockites. Only person i've ever seen stand at the steps at Ginnie and ask someone "does you wife know you dive backmount?"