This is a very HN sort of sentiment. How can I be persuasive without being gross?

I had a bit of a moment when I first became a PM. (I've done a bunch of things, engineering / sales / founding, but PM only sort of recently.) I realized that my job was to wake up in the morning and pick fights. Or more diplomatically: to tell people they were doing the wrong thing, and they should be doing a different thing, in a way that made them want to listen to me more in the future, not less.

That's the job. In fact, in almost every job, that's the job.

Impact happens when you reach people and they behave differently because of you. That's nothing to be ashamed of. If you do it authentically and with good intent, it's one of the best things you can do with your time.