Except totally unreasonable :)
Rockets that size cannot be launched anywhere near populated areas, so they'd have to launch from off-shore platforms; outside of Australia, USA and Russia there are no worthwhile destinations that can safely host on-shore rocket launch complexes for that class of rocket.
This poses quite complex logistical challenges that enthusiasts just love to handwave away. But there's even more to it: airspace needs to be closed on both launch and target sites.
Weather will lead to scrubbed flights as rockets have much tighter weather parameters than aeroplanes and are incapable of changing routes mid flight or divert to alternate airfields.
The most ridiculous part, however, is passenger logistics: every astronaut/cosmonaut/taikonaut wears pressure suits during ascend, since otherwise there's no way to breathe in case of a loss of cabin pressure once you're above 20km. Oxygen masks just won't do anymore at such heights.
This means passengers would need to wear and familiarise themselves with pressure suits, unless SpaceX can convince the FAA somehow that even fewer failure modes can be mitigated while still being safe for passengers...
Getting onto the rocket is another point that's far from trivial - one doesn't simply walk into Starship and pick a seat. The seats wouldn't be upright, so passengers would need to climb into them and be secured by personell. Not to mention the elevator ride and the long wait during fuelling (remember: SpaceX are the only ones who do "dry-loading", that is they only start fuelling once the passengers are on board).
So your 30 minute short trip from LA to Paris would in reality consist of a 1 hour drive to the port, followed by 1 hour check-in and a 1 hour boat ride to the off-shore launch facilities. Next you'd have at least 1 hour of boarding procedures (limited elevator space, pressure suit fitting, seating) followed by fuelling (maybe another hour?). So after about 5 hours or so you are finally clear for launch and arrive somewhere off the coast of France 30 minutes later. From there it's another hour for unloading, an hour to get to the coast and another two hours from the coast to Paris.
In total, best-case scenario travel time would be about 9½h - better than the 16h via plane (12h flight + 4h getting to-/from airport plus boarding time), but a far cry from Shotwell's "business meeting in Abu Dhabi in the morning and back in Vancouver for dinner".
The off-shore launch platform idea isn't mine, by the way - the concept was brought forward by SpaceX themselves and presented by Glenn Shotwell who said "the longest part of the ride is be the boat out and back" [1].
I'm highly sceptical of the idea - not because I think it's impossible, which it isn't - but because the logistics, regulatory conditions, and economics behind it just don't make sense. I could be wrong, of course, and stranger things happened, but realistically, the odds are very much against this ever going to happen[+].
[+] using Starship/Super Heavy as envisioned and developed today
[1] https://www.youtube.com/watch?v=Dar8P3r7GYA&feature=youtu.be...