I have a Technics SL1210M5G and I *do* use the speed control once in awhile. I have the rare, out-of-print and normally expensive 2-LP Classic Records release of "Kind of Blue." It has the original incorrect speed version of side one and the speed corrected version on the other side of the first LP. I got it for $5 at a record swap meet because the corrected version of side 1 is crackly and noisy. The uncorrected side is quiet and perfect. So I play that side and use the speed control to correct it.
I also practice bass by playing along with records. Many records are not recorded at A440 pitch. In some cases the musician may alter the tuning or it may be that the mixdown or mastering speed was altered. Anyway, I don't want to retune my bass every time a song is off-pitch, so I correct it with the speed control instead.