Given the 'length comparison games' that Branson and Bezos have been up to with their 'near space' escapades it's a massive F U for Elon to do a trip like this which will actually be one of the furthest distances humans have gone from Earth since the moon landings (the orbit is higher than low-earth orbit where the ISS and Chinese space stations are). There's no question these people will become fully fledged astronauts.
I was wondering if shareholder issues and risk could be the problem - but it's not like Elon seems to care about that and Elon is already saying he's going on Virgin Galactic anyway.
Elon, Grimes and two friends going up on a Dragon X capsule for 3 days would be a hoot.