[erics32]

mattmcknight's comment addresses one of the reasons.

I think another part of it is a lack of understanding of what developers actually do - people perceive developers as manual laborers that just type stuff into a computer based on what a higher-up has designed/created. They attribute the actual creative/engineering output to the manager.

It's also a low-paying job in a materialistic society. There's a feedback loop of Low pay -> no respect -> low pay that's hard to break out of.