Security ... think about it!
And, then there’s the Astronauts4Hire initiative – with a collection of young up-and-coming space scientists vying to get their training at the aforementioned facilities sponsored so that they too can “get in line to fly.” They’re marketing themselves as burgeoning commercial suborbital payload specialists, the idea being that when companies/universities/etc. want to perform suborbital research using the new spacecraft around the corner, it’ll be cheaper to hire these guys than to train and certify their own staff for spaceflight. -I think it’s a fantastic idea. Heck, I’d be jazzed to sign up with them one day if the opportunity arose.