All these aristocrats were in fact tolerant because they view Camilla with the same indulgence the way they view any kind of kindhearted mistress in a brothel. A 'nice type,' but still, only a mistress. If Camilla were still a mistress, she would still be sitting several rows behind the regular royal party.
Camilla would not have "won" had Charles married a woman (the first wife) just as hard hearted as Camilla--someone who had no intention of giving Charles a divorce and living it up enjoying the perks. And even playing nice with Camilla. Though Camilla would have sent a woman such as that off unless the woman was a skilled actress.
Thing is, that, what makes what Camilla did so hocking is how she destroyed a marriage between a Prince and Princess of Wales; no one other than Diana likely viewed Camilla as anything other than a predatory mistress and liked perks and wanted to maintain her position, nothing new in that set.
The difference now is that Camilla literally threw the wife off and this is what must have shocked the courtiers; threw the wife off, blasted the wife's rep, and then ended up marrying in, only creating more work and stress for the courtiers who have enough problems as it is when it comes to keeping the Windsors on track.