Welcome to the forum Pantemon
I think basic graphics classes are a waste of time. Ditto for basic web design classes. However, I do think that a degree in graphic design would be extremely useful. My flatmate has just completed a degree in design and her knowledge and ability to analyse graphics and designs is quite impressive. I don't think you could learn those sorts of skills yourself - well, some people do, but they're more an exception to the rule.
Taking a course to learn how to use software is a complete waste of time IMO though. I haven't taken a lesson in how to use graphic design software, but I have taken an advanced course in MS Word. The MS Word course was pointless, I learned more from online tutorials on MS Word than I ever learned from the MS Word course.