Being structured is often confused with being serious, while you’re just really focussed on what you have to do. This could mean that you have less time for friends, going our, or that you go to bed early. I don’t really see this as a problem, as long as I’m getting the results I’m going for.
Second: I’m not that serious all the time. I want to write compact and dense newsletters, and that means that there isn’t much space for ligher stuff. But trust me, I do procrastinate from time to time. And I don’t think it is bad.
My main point: be intentional. Others will think stuff of whatever you do, but it is up to you to really figure out how you want to live your life.