i've been ditched, but it's usually mutual.
i'm a glorified hacker, but I tend to go a little slow on the steep and deep.
i also tend to ride with folks who are definitely a level or two above me.
the cool thing is that for the most part they aren't so concerned about hitting the fresh, untracked and being the first ones on it. they're more into us all riding some sweet lines and then getting all hyped to repeat the performance on the lift (this would be when I ride with my cousin or my old college roomie).
I got ditched by my buddy Ryan a few times last season when we rode together in Utah. First day was at Brighton and I kept up for the first half of the day, but then he just jetted after lunch. Same thing happened at Alta the next day and Solitude on the third. By then, though, I was like "Dude, when I can't keep up, just go. We both know where the car is, have cell phones, and are experienced/smart enough to know where we are and what to do if we get in trouble." There were no hard feelings (I'm 10 years his senior, so he's got a little of the youth juice cranking through him still) and he always calls me up to see when we're going to hook up and ride again, so it's all good by me.
But I think I echo some of the above sentiments. I'm more happy riding with somebody, even if they're slowing me down, because it's often more about the comraderie than grabbing untracked.
I also tailor my day based on who I am riding with. I know that when I ride with either of the aforementioned folks (cousin/college buddy/young buck buddy) that I have to step up my game and make every attempt to not hold anybody back (this usually means that I attack the run first and let them catch up and pass me, thus narrowing the wait time for them). Conversely, if I am riding with somebody who is slower/less skilled than me, I tend to take it more mellow and not worry about how much fresh or how many runs I get in. I'm actually trying to get more zen and less anal about riding. I used to count how many runs I got in, refused to take lunch, and ride til last chair. Now I'm cool with getting on the hill some days at 10 and taking a leisurly hour lunch break and quitting around 2:30 if the mood strikes me. I'm also hella cool with being on the lift at 8:30 and riding until 4. It all depends.
I also ride a lot with my dad, who is 75. He has good form, but takes it mad easy (Greens and easy Blues). When I ride with him I feel obligated to get in a few runs with the old man. Lord knows he spent a good deal of his prime ski years with my whiny a$$ wedged between his knees. Usually I'll ride with pops in the morning and then at lunch he'll cut me loose and hit the lodge for coffee and a nap back at the car.
Again, it all depends.
But for the record, I rarely ditch unless the person I'm with says "Dude, go ride your double blues and blacks and meet me at the lodge for apres action."