Spock mind-raping Valeris
It was a piece in the evolution of the Vulcans as "not very nice people" that Star Trek did over time.
The Vulcans were
never portrayed as very nice people. Look at TOS. Sarek doesn't speak to his son for umpteen years because of a family tiff, and is briefly suspected of murder. T'Pring is a schemer who is perfectly willing to get Kirk or Spock killed to get what she wants. Even T'Pau is pretty icy and disdainful of Spock's human roots. She also seems to value preserving Vulcan traditions over the risk to Kirk. ("Amok Time" is great, but it always bothers me that nobody bothers to explain to Kirk that the battle is to the death until
after he accepts the challenge. Good going there, T'Pau!)
And, of course, it was D. C. Fontana, the authority on all things Vulcan, that established that Spock was bullied as a child by the other Vulcan children.
I'm not sure where people got the idea that Vulcans started out as paragons and that it was the
later shows that sullied their reputation . . . .