Couldn't agree more. Heuristic to use when someone is bashing someone else's code: Have you contributed (money, code, docs) to the project? If the answer is no: person lacking skin in the game - irrelevant (even harmful) armchair comment.
Bad software is bad software regardless of who has funded it, who has committed code to it, or who has written its documentation.
One does not have to be a contributor to that software in order to analyze it and make a judgment regarding its quality.