The problem isn't knowing how transistors work (although in the old days, you often did learn something about that in the process of learning computers), but rather not even knowing how basic code structure works at all, or simple required math, or logic. Not knowing the absolute basics of code and then thinking you're a "coder" because you can blindly copy/paste code without understanding it on any level is straight-up dangerous.

Sure it's a problem if that code ever needs to be fixed or maintained. Or if it irreversibly alters data in a way that the "coder" didn't understand or intend. If it's a prototype or some kind of one-off with limited side effects, I guess there's not much risk.

Well, it's hard to solve a problem you don't understand right? When a problem fundamentally lies in a domain no one understands, how will it ever be fixed or solved? Best you can do is paper over the problem in some way, or somehow get randomly lucky.