It does seem that the emotional suppression movement was a life-or-death drastic response to the conclusion that Vulcan passions and violence would ultimately destroy them.
I don't think every pre-Surak Vulcan was a raving berserker, but I guess enough Vulcans were dangerous enough to incite such an extreme rejection of emotions.
Joke's on Surak, though, as seemingly survival with emotions was
possible--the Romulans proved that.
And then, yes, we have Vulcans like Sybok and those ENT fellows, who live with emotions and are not raving madmen or violently destructive.
Millenia later, I think it is possible that logical, emotionally-suppressed Vulcan is a philosophy, a long-held cultural tradition deeply ingrained and widely accepted, not necessarily a biological imperative (although yeah, Pon Farr).