Last I knew BUMP stands for "Bring Up My Post" so technically you should be bumping your own stuff.
But for reals, some people only get on during certain times of the day, so if a thread was made in the afternoon and nobody replied before nighttime when I log in, I might miss out on a thread that I would have been really interested in.
I think it depends on the timeline and section of the forum its in. If you post in ski gabber, and it doesnt get much attention for that day, it will be gone off the first page very quickly. If you post in gear talk, it will probably float around on that page 1 for a few days, even with noone posting in it. I think its totally fine if its once every now and then, and totally relevant, like not trolling kind of thing.