DJs have been using Thorens TD-125 mk II belt drive turntables in the late 70’s, here is a picture of the dj booth in Studio 54 (NYC) with Diana Ross on the mic. Same turntables with Infinity Black Widow tonearms and Stanton cartridges were in use at the Paradise Garage club in 1979,
Clubs like 54 didn't do scratching or other manipulation (interference) with the record's normal rotation — so Thorens and other belt-drive was fine. Start the Music, let it play, mix to the next track — the whole idea was a consistent rhythm for the dancers.
'Turntablism' started with Rap/Hip-Hop in the early-mid '80s. Belt drive couldn't do it, high-torque direct-drive was perfect, thus the 1200 took over. It was more a 'musical instrument' than it was neutral playback device.
So I think your "brainwashing" comment was a bit OTT
I was DJ in '66 at a NY club called Steve Paul's "The Scene". The two turntables were Bogens, with a simple cross-fade mixer; it's all that was needed. All records were 7"-singles. Beat-matching was essential for consistent dance energy, and a transition to slower tempo/mood both for body-contact dancing towards the end (a main purpose of the clubs was to hook up for after-hours) and to lower the energy so the floor would clear for the Live acts.
"The Scene" had great dancers, but is more famous for the musicians who played there live. One block off Broadway, chorus line dancers from the Musicals flocked to The Scene as soon as the curtain fell, to do their own creative dancing
to James Brown, Wilson Pickett, Motown, after 2 hours doing trite, polite, paid choreography to show tunes. Best dancing I'ever seen.
But the club's highlight was the Live Acts: The Doors, Cream, Traffic, The Velvets, Steppenwolf, Hendrix, Joplin — just about every major group from the Sixties who had a big gig in New York jammed at The Scene, and sometimes jammed together. Example: the live act for one week (advertised and paid) was the Muddy Waters Blues Band (2 sets every night: 9 and 12). And every night, unpaid and unadvertised, Hendrix came in — he sat in back of the stage, and played lead guitar. Few knew it, because a) Jimi was shy, b) didn't want to upstage Muddy; and c) sat behind the amps and speakers against the rear wall, nearly hidden.
Starting in the early '60s, all the clubs were called "Discos", but changed radically as the culture, music, fashions, drugs (especially "The Pill") changed. And "Disco" as a musical genre only started in the '70s.
I guess it came to an end when 54 became too involved with drugs — but I was long gone by then, my club days/nights were only '66–67...