Some people who studied compsci at university chose that because they'd been coding since they were 6 years old and they absolutely love it and want to master it. They're not all there because they decided it pays better than law.
Students will often gravitate to majors that have some overlap between "This is pretty interesting" and "I can probably make a reasonable living doing this." Outside of the arts, programming is rather unusual in that some have an expectation that this is something that you've loved since you were 6. (And, again, CS only overlaps to some degree anyway.)
Amazing what someone wanting to see "something" will see "something"... if anything , going through the pain of a CompSci degree and not giving up (more than half my class gave up in the first 2 years) is about the best proof you can get the person is interested in programming.
Self-taught people may also be truly talented and interested, but it may just well be that they studied for a few months and now claim to "know programming" exactly because they noticed the profession pays very well (I know someone exactly in that situation right now, and she's already looking for some other path after just 2 years in it as clearly she has zero aptitude).
