No, they're sore over GameStop's CEO making millions a year without contributing to the industry writing his check.
And no, they can't simply lower prices. This argument makes my head hurt. If they lower prices used games lower prices. Eventually they hit the point where they're not making enough and you see studios close and more contract work going out. Raising prices is actually a (slightly) better option, as you capture more money from the people that prefer to buy new. But getting into a price war against used games is a death spiral - they'll always be able to undercut you and people will continue going for that $5 savings.