I should have said the monadic form of Option<>. When you use it monadically, the result is nearly equivalent to exception handling; you call a function and the default behavior is to bundle up the error and just throw it up. It is true that if you are manually unwrapping it every single time, it's equivalent to checking every time.

"For Golang programmers, "return err" is muscle memory."

First, as I said, no, I actually think about it every time. And second, I bet you end up with "muscle memory" default handling under any scheme (for instance, exceptions: don't catch them or rethrow them)... in the end, you can bring the horse to water but you can't make it drink. You can only feel good that at least you brought it and you did your part. Option<>, even manually unwrapped, does not force the programmer to do something sensible with the error any more than any thing else does, or indeed, can.