Fortiter, I suspect you are coming from having done turning for years and, having seen a 1000 collars, are tired of them. But maybe having seen a 1000 vessels without collars, others are equally tired of looking at the same shape and want to change it. Like many have said, if a collar is an intrinsic part of the turning and adds to the artistic statement I like it. I don't like collars just added to a piece because you decide to add a collar.
I guess I have the same thoughts about much in woodturning. The same old bowls, vessels, spindles, turned the same old way out of the same old wood, gets boring. How many times would you buy a piece of pottery that is exactly the same as 20 others that you already own? But we often do that in turning. It gets trite.
So I say if you are going to add a collar to help create a new form or a new way of expressing an old form, go for it. If you are just going to add a collar because it's what you do, it's going to look trite.
Earl