Hmm, bit of a double edged sword though I’d say. Speaking as someone who does stand up comedy on a regular basis often times starting out your set with self-deprecating jokes works well to help win the audience over to your side. There is the risk of course that you might encourage a heckler, but I still think it is worth the risk.
I think it is the same with writing. Adding some humor may turn off some of your readers, but I would imagine the majority of them would find it easier to identify with you when there is something to laugh at and, if it’s done right, laugh at themselves as well.