Programming is programming regardless of the platform. I've had clients and projects I didn't like, but generally speaking writing code is fun for me.
I have nothing against someone who has an idea in some unexplored niche where there is little money to be made. However, there is a word for someone who takes a job to work on someone else's vision who doesn't care about the money they make - chump.
I guess as the hirer you probably do want the hire-ee to ignore they pay so you can maximize the benefit you get out of said chump. And hey, if you can get away with it, more power to you. We're all consenting adults here. I doubt you'll be able to consistently find any but the least experienced to fall for it for long though. Great developers tend not to be chumps.