Technically, the concept of LARPing predates any table-top games taking on a role-playing aspect. It was initially popularized in the '60s by groups like the Society for Creative Anachronism and then applied to medieval wargames, which in turn spawned D&D. Splitting hairs, I know.
Edit: Apparently Wikipedia would have you believe that LARPing and being a historical recreationist are two different things, where LARPing necessitates a game of some kind, but that strikes me as a revisionist take. Historical recreation begat TTRPGs (at least in part), which begat LARPGs? I guess. I'd personally say that any time there's a well-understood shared world that you're participating in, you're LARPing.
Speaking as someone booked on the Starcruiser for mid-April, the LARPing aspect is what makes this unique and (if done well) worth the cost. I am not a "major" Star Wars fan, nor am I an aspiring actor, nor do I frequent the Ren Fair circuit, but I think it seems like a fun and interesting experience. Trying to figure out what our wardrobe might be and debating which side we want to play has already been a lot of fun for me and my spouse. We shouldn't underestimate the possibility that there are plenty of people out there like me who don't fit into an easy category, but would still be interested in this. After all, there are over 10 million active players of D&D alone.