Pink Floyd may be the most well known prog band, but they're not the most influencial or important band to prog, King Crimson and Yes both surpass them in that regard.
Some of the more snobby prog fans tend to be more harsh towards Floyd because they didn't employ the kind of technical chops that other prog bands did, the production was more slick, they relied more heavily on production techniques to achieve their sound, and their music was less structurally complex and more accessible.
They still have a pretty big influence on many prog bands.
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