Because programmers probably think it'll be a similar field, but it's different. It has correct and incorrect ways of doing things, strongly enforced. You're not inventing new shit, you're reapplying old shit constantly. Old shit that works.

Many think writing software is engineering, but it couldn't be further from the truth.

edit: to clarify, trying to get people to realize the grass isn't always greener, and both sides are better off for it.