It does seem a natural thing to happen, but from what I understand, it's not that Vulcans have no emotions; it's that they have to suppress them for the sake of themselves and everyone else. From what I recall, the Vulcans before they suppressed their emotions were more like earlier humans - brutish, prone to making important decisions based on feelings, etc. It's certainly possible that they could reconcile those emotions with the logic they've mostly mastered today, but it can get iffy as we see with T'pol in ST:ENT. I also think Vulcans are used to give that "purely logical" viewpoint often to counter how we humans have a tendency to fly off the handle. It's not always the right viewpoint or the one that works out best but it's nice to have that different perspective.
I always thought the Vulcans were throwing out the baby with the bathwater on that one. Possibly they were even fooling themselves a bit on how destructive their emotions were. The "Vulcans without Logic" on Enterprise were (mostly) fine.
Kristie Alley's Saavik is actually my favourite Vulcan because of her more emotional behavior It's (imho) nice to see members of a Alien Species in Star Trek that don't follow their species' stereotype 100%
As to her being half-Romulan, my stance on that (and I know it's a bit immature) if it wasn't in the movie, it didn't happen
