I certainly think some people do this. There are a couple ways around this I've used. First, I'll say that I will come back and do a presnetation or two (couple lunch hours) on things I learned. That often spreads some ROI around to the others at the company. We used to rotate who could go, and everyone had to share, so that others that didn't go this time still learned something.

Two, it is a bit of a perk, but it's a tax deductible one for the company. This is a good way to give you something you appreciate without costing the company more. It helps with rentention and ensuring good people don't leave. I always point that out.