I'm living with my parents as well, with basically the same arrangement (attic instead of basement). Personally I'm dreading the day I have to move out, because of how hard it will set back my FI date. There is no way I would be able to maintain anywhere near my current savings rate (unless I got a huge raise) if I were living on my own. I'm 22 now, and have no plans to move out anytime soon. I have no idea how much money you have saved up, or what property prices are like where you live, but if I were you I would figure out these numbers and look into how much money buying a house will cost you, and how that plays into your FI date.
I do agree that living with parents has some downsides, and I feel you on the 'scorn' part. I imagine these problems are slightly exacerbated by being single, in terms of bringing home prospective dates etc etc, but I don't have much experience in this regard. On the flip side, it sounds like you get to spend a decent amount of time on the road, which probably lends some feelings of autonomy? As you mentioned, buying a house locks you into a location for quite some time, do you see yourself at your current job for a long time? If the stigma is whats getting you down, I might try renting first and seeing how you like it? WAY less of a long-term commitment. I'm firmly of the belief that keeping your options as open as possible results in a much more exciting and enjoyable life!