I'll take the results at face value. I know plenty of coders who are motivated solely by income, and they get much bigger contract rates in the J2EE market. The fact is, a lot of beginners and hobbyists have entered the "P" market (more so in the PHP and trivial Perl arena), and they drive down the rates. Increasingly script language web development is going overseas to the lowest bidders on the reverse auction sites - and they're hard to compete with if you're currency doesn't compete well with Eastern Europe/Asia. So consequently, a lot of my peers stick with the so-called enterprise languages to protect their income.