Considering what an abstruse art most ordinary folk find tomato pruning to be, as evidenced by tens of thousands of viewings of this video (1:41), Mr Greenthumb aka Stan de Freitas delivers a startlingly short and simple lecture.
Standing in the St Petersburg, Florida garden center where he is the resident pruning guru, MGT says you prune for a couple of reasons, namely to get rid of suckers (that’s nursery speak for new shoots) and to cut out problem areas such as leaf mite, mildew, fungus etc. He doesn’t say why you want to get rid of those suckers but presumably it is to limit the ranginess of the plant.
MGT makes a big deal out of making a quick, clean cut. He doesn’t say if tomato plants are sensitive to pruning speed. That seems unlikely. It could be that the retired folk in Florida fall asleep with their sheers in their hands when pruning their plants and he feels the need to warn frosty-top tomato growers that they need to guard against this real and present danger.