I think the key here is Severe turbulence. In my entire airline career, I have only encountered it twice, once in a 737 and later in a 777. The second instance had the stall warning and overspeed going off simultaneously and the instruments very difficult to read, so the speed was only really an average, over which I had almost no control at all until it was over.
Some fly around at turbulence speeds a lot, just in case, and some have never felt the need. I was exposed to the whole spectrum of opinion so probably fall more into the latter camp. If I had a report from an aircraft in front of Severe, then I would get everyone sat down and the speed appropriate, assuming I couldn’t avoid it laterally or vertically. Rest of the time I put it somewhere in the middle where it generates the least paperwork...