No they just see emotions as useless/illogical iirc. They don't see any logic in emotional reactions so they reject them.
Though the more I think about it the more sense it would make for more Vulcans to do this as it would end a lot of the typical misunderstandings and awkward situations.
I think its worth remembering that most vulcans allow some emotion in interpersonal relationships, especially older vulcans. Spock is just trying to be super duper logical to prove he's vulcany enough even with his half human heritage (which is ironically an extreme emotional reaction)
Actually they are hyper emotional by nature, which has given them a lot of grief (in the form of brutal violence and wars against each other) over the millennia until one guy came up with their philosophy of pragmatic rationality, which as its core element asks vulcans to learn to ritually suppress their emotions.
It isnt so much them considering emotions as useless, more them being very wary of them due to their past, and their philosophy/belief system teaching and emphasizing rational thought as paramount and the highest ideal, and (their) emotions being fundamentally irrational. So they are often a bit miffed when humans for example make obviously emotional decisions.
IIRC the cause for the split isnt completely fleshed out, but supposedly it happened around that time with the romulans rejecting the new philosophy. I am not sure if they simply left or were exiled though.
What I also find interesting in this regard is that the vulcans are slightly telepathic, and the romulans are not. Perhaps it is an ability that developed from generations of mental discipline the vulcans went through.
Another fun (and not very likely) take I once read is that the vulcans we know are actually augments, similar to the ones earth made and banned after they became tyrannical.
The theory here being the original vulcans (physically romulans) tinkered with genetic engineering, creating the modern form of the vulcans with increased mental capacity and psionic potential, also losing the romulan forehead in the process. Then they would go the same route as the human augments, paired with their violent emotions, and start a civil war with their regular brethren who then eventually lose this war and leave or are exiled.
The new vulcans then start warring with each other until eventually surak shows up with their modern philosophy.
Trouble of course is if they feign emotion but are not convincing to their hosts they'll alienate people even more than if they just act in their natural Vulcan way