I don't put my bulk loaders on display, they live in a drawer under the bed. They are, however, practical pieces of kit that I use regularly. I generally have two or three different films on the go....currently my three loaders have HP5+, Fomapan 100 and Kentmere 400 in them. Never had any scratches, I find them quite easy to use. For the record I have a Watson 100, a Prinz 66 (rebadged Watson 66 I think) and a "The Daylight" which is the simplest of the three. None of them causes any problems, and as well as meaning I can roll a few films without getting out the changing bag they are secure ways to store my bulk rolls.
It's certainly not strictly necessary to use one, you can go in a dark room (proper darkroom or your windowless bathroom) or a changing bag and roll a few cassettes off a bulk film...but it's probably more fiddly and risky if something goes wrong and you cannot count frames. It all depends if it's important these things are.