It raised mine by more than a few mm Hg
As someone that has been a moderator for several years and seen countless examples of what I call “profile spam” I beg, please no.
To this day there are a large number of account registrations every day, the members reading no posts, making no posts, but populating their profile to advertise a business. And this with profiles that are only visible to other registered members. I can only imagine this would become even more of a problem than it already is if they became indexable.
True, there might be some value in exposing links to posts to search engines, but they are already exposed elsewhere and don’t need to be also exposed from profile pages.
EDIT
trust level 2 and above could work. By the time a member makes it to trust level 2 they can be, ermm, more trustworthy.