A nightclub was a very different beast in the 1980's. Suits, carpets and lots of beer was the formula. Violent, unsophisticated places, but they made good money.
Then, in the early 90's, drugs started to take a proper grip on the nation's youth.
And some of those existing nightclubs bought into the new culture. And some did not.
The owners of the ones that did, in the main, continued to have a great lifestyle and through mental gymnastics (and intellectual dishonesty) they justified what their nightclubs had become associated with, even if that was something they'd previously rejected - because it was keeping them in a lifestyle they'd become accustomed to - and felt they deserved. They turned a blind eye.
In an uncertain world, people are nearly always going to want to protect something that gives them a degree of financial certainty and status. That's just the way it is.