Is there some selection bias in my data set that I'm unaware of?

Yes. You are looking for a Java Contract Developer, who happens to have a H1B visa. There is a very high chance the majority of people you would get to interview would be ones who are below average programmers, and are in to this profession only for the money bit and not for the love of it.

As mentioned in this thread, majority of H1Bs are lapped up by the big services firms and body shoppers. Not many would be willing to leave a permanent job in a big firm and apply for contractor position. But yes those who went through body shoppers and are just looking for a better pay package would queue up to interview for you. Sad but true.

So your selection set really is "mostly" bottom of the pile programmers, and hence such hard luck for you.

On your observation about general lack of creativity, these people are probably not the best ones to form an opinion, but yes our education system is to partly blame for it.