We'll have to disagree about the axes---I think the choice of where to start axes depends on what you're trying to illustrate. For me, absolute differences in wages was what I wanted highlight.
Re: Standard error bars - you're absolutely right. I should have included them, but it was my first time using the googleVis package & didn't see an easy way to add them. I don't have the numbers right in front of me, but standard deviation for each skill was on the order of ~$7/hour and each skill had to have at least 30 obs., though many where much, much higher. If we say n=50, that's an SE of about $1/hour, so clearly one shouldn't take much stock in very small differences in wages. My goal was just to unearth some interesting data---I probably should tone down the implied recommendation lest I'm responsible for a glut of unemployable lisp hackers in a few years:)