Spock isn't a full Vulcan so shouldn't be seen as a template for the race. So his reactions in Amok Time can't be assumed to be typical.
If you look at Phase II, Xon shows a lot of the pre-retcon approach to Vulcans - in essence he is Phase II's Data, trying to understand, and even fake, emotions he didnt have in a vain attempt to understand the human crew.
Sybok is a fair point, though, coming about a year before the "Sarek" episode and also retconning Amanda Grayson as Sarek's second wife. Iirc. So perhaps it can be seen as the beginning of Vulcans-are-humans-with-pointy-ears-and-an-unhealthy-fixation-on-surpressing-emotions.