The estimates I've seen were more 1/3 to 1/2 of people being infected but it is very common because most people engage in unprotected kissing with a number of partners. I have, in fact, never heard of anyone using a barrier while kissing so I don't think you can expect that someone with HSV-1 to also have other diseases.
My sex ed class taught me to use a dental dam for protection while kissing. I guess some people got abstinence-only classes, but most of us were taught how to stay safe.
I've also known multiple people in the USA who actually succeeded with abstinence. They did not kiss or spend time alone with the opposite sex until their wedding day.
IMHO the abstinence looks easier, but the use of protection is being taught.
