What do men think of enlarged labia?

Varies. There is a branch of cosmetic plastic surgery dealing with labia that are enlarged. This is probably an issue in the mind of women discovering this and wanting what to their minds is a more pleasing cosmetic appearance. Men largely have no issue with this either way; there is a sub set of men who actually prefer that appearance and would be disappointed if altered.
The Individual . Men do not all follow in one attitude about anything. Some like larger labiae and others like them smaller. Women consider labiaplasty for their own reasons. Men are rarely involved except indirectly in most happy patients.
Eye of the beholder. Beauty can not be judged or dictated by any one individual. What one person may find attactive, another may find repulsive. Given my experience and the varied responses of the public to labia reduction surgery, there are men who love enlarged labia and find them beautiful while other prefer less prominent labia.