[AndrewOMartin]

Yep this. It's fundamental supply and demand economics. It happens in any sector that's perceived to be fun or attractive. See also 'work for exposure' in photography and music.

It seems to me that the on the opposite end of the scale you have Database administrator. Pretty much all non-trivial software projects need databases, their proper administration is absolutely essential, and it's the least sexy sounding role in a software team.

My (completely untested, and semi-serious) career advice is to read a reference manual for a database like PostgreSQL cover to cover.