I'll take your word for it (I'm in the lack of knowledge camp), but I don't see this as an argument for not raising the marginal (and if we do it right, effective) tax rate on the very wealthy.
It's not. It's a counter to the justification of 'we did it before.' We didn't, not really. If you want to raise the marginal tax rate now, it needs to have its own justification independent of historical marginal rates since it's not an apples to apples comparison.