I agree 100%. I'm going to use Sam Jackson's speech to Bruce Willis from Unbreakable as a point here.
There are some villains that just work better as thugs, like Electro. He's a glorified thugs. They test the hero's physical strength. Then, there is the archvillain, a person usually closely associated with the hero, who tests his mind. This would be Green Goblin or Doc Ock for Spidey.
Then, there's the misunderstood villain. This villain does bad things for a good cause, like stealing to help pay for treatment for a sick child.
The problem is that often, thugs need a little bit of fleshing out. Especially super-powered thugs like Electro. Using throwaway characters that weren't originally created to be throwaways, like Omega Red, is bad writing. So is taking a character concept that could work with a little ingenuity, and then throwing away said concept.