Ask HN: Bad idea to have side projects at early stage startup?

The title says it all - I’m wondering what the HN crowd thinks about working on side projects while working fulltime at an early stage startup (~10 employees). Would love to hear from both from the founder and early employee crowds.

While it goes without saying that the projects don’t interfere with my work responsibilities , they do prevent me from putting in extra time - weekends, nights, etc - which isn’t expected, but I could certainly be giving more.

I know that leadership is, at least on the surface, fine with employees having side projects. That said, I worry that it signals a lack of interest / motivation in the company. Is this a bad look, even if it’s nominally “OK”? Are early employees expected to be “all in”?

Part of me also wonders if I have to work on side projects to be fulfilled, why am I working at an early stage company instead of big co; but that’s perhaps a seperate question.