I'm a triathlete, and i primarily train for the long course stuff (although short course is fun too).
Perhaps it's just this area, but i don't get any attitude from the pure roadies. Sure they think running off the bike sucks and only fools do it, but to be honest, they're right. Since that's assumed by both of us, we get along just fine. In fact, many of the multisport guys and roadies are good mates and ride together all the time. Around here, if you can hold a line and hang, it's all good.
Doesn't hurt that most serious triathletes i know are just as fast as most of the roadies in TTs, group rides, and cyclocross.