I'm not a native English speaker, but I thought "you can't do well" is equivalent to "it's impossible to do well", which is how I read the original sentence.
As an aside, I find it a bit ironic that you're complaining about pedantry while interpreting the "you" word literally.
It’s not ironic that my response was pedantic, it was the entire point. When you engage in pedantic nerd sniping you just open yourself up for even more pedantic nerd sniping.
“Can’t” can mean impossible, or it can mean nobody can do it. Compare “you can’t go back in time” with “you can’t lift a horse”.
As an aside, I find it a bit ironic that you're complaining about pedantry while interpreting the "you" word literally.