When I was considering a career as a musician and actor in middle school and high school, there's a piece of advice I was given many, many times by my mentors and teachers: "Only pursue a career in the performing arts if you can't see yourself being happy doing anything else. It's hard. You will face countless rejections, and even after that you'll most likely never make it big. But if you can't see yourself being happy do anything else, go for it."
If you think you could be just as happy working for a large company, you should probably go do so. Entrepreneurship is tough, and if you can find satisfaction from a job that doesn't have the monumental downsides that doing a startup does, you're probably better off steering clear. If that's not the case, and if for whatever reason you can't imagine yourself working anywhere other than a startup, do it. Don't feel like you need to tell people that they're doing it for the wrong reasons, or that you need to justify your own reasoning to those sorts of people.
If you think you could be just as happy working for a large company, you should probably go do so. Entrepreneurship is tough, and if you can find satisfaction from a job that doesn't have the monumental downsides that doing a startup does, you're probably better off steering clear. If that's not the case, and if for whatever reason you can't imagine yourself working anywhere other than a startup, do it. Don't feel like you need to tell people that they're doing it for the wrong reasons, or that you need to justify your own reasoning to those sorts of people.