I gotta agree with what appears to be the majority on how the situation shoulda/coulda been handled better. I guess a question for me would be, do you REALLY HATE your RV, or do you hate the fact that you're having issues. You wanted the dealer to fix your issues, but you, in essence, trashed his product, in front of another customer. I probably woulda told you to take a hike too.
I've been where you were at.. problems with a dealer (albeit car dealer). I don't use the dealer anymore. I was cordial, polite, but firm in stating my problems, in front of other customers who were waiting at the service department. Had someone asked me how I liked my Dodge Challenger at the time, I woulda said, I love the car, just not happy with the current maintenance issues at this time and left it at that.
If you hate your RV, regardless of it's current state of repair (or disrepair), fine, but there's nothing wrong with stating that in a more reasonable and measured fashion. It's not about being politically correct. It's about being reasoned and measured in your evaluation.
I too do not believe the dealer owes you an apology and I would probably not even accept one from you if you wanted to come back. And I've never been known to be politically correct.
Mike