You should be careful! I mean this sounds logical, but taken to the extreme, it would mean that you judge people who are racist and actively support genocide even though they are always nice to you (assuming you are white). Do you really want that?
Text doesn't convey tone, and not everyone who reads what you write knows you personally. The /s doesn't ruin the joke near as much as the person who thinks you are being serious does when they raise a shit-fit over it.