The main reason for what you've observed is that those smart folks that could be a good fit for the project probably are a good fit for many other projects, inc

The main reason for what you've observed is that those smart folks that could be a good fit for the project probably are a good fit for many other projects, including many which use the technology they do like. Good tech people generally have an opinion about technology (duh), so they like some technologies and dislike others. If I can make $X from working with PHP or make $X from working with Rails, why should I work with PHP when I dislike it? You should consider whether you really are in a position to determine the choice of technology. If they are smart people, and they know tech and you don't, maybe they're aware of more problem constraints than you are, and you are actually the short-sighted one, not them. You don't hire an expert musician who has mastered a dozen instruments and then tell him he's only allowed to play the oboe for the next two years. Being able to make your own technology choices is one of the attractions of running your own business (as a technologist). By imposing that externally, you take away a lot of the positive. Another thing you might want to think about is what else you can offer these people to entice them on your project. Always assume that they have many other similar options that you're competing against (this will be true for the good ones).