Paul and
Caroline are more mainstream than
Beulah, which I think makes a difference, but I do realize a lot of people don't know or care about name meanings.
My point was I don't think the meaning by itself would sway many people into using it, if they did look it up...and it's odd enough that if people were on the fence about using
Beulah, finding out the meaning might convince them not to. So, it's just more unlikely to catch on because of that factor imo.