Probably mostly time and cost. You can do Bart and Muni to the new arena from Oakland but it won't be quick. Also late night Bart doesn't run very often
Shortsighted of the Warriors to not have implemented something that could've made it possible for their workers to keep their jobs, even if that was setting up a private commute/transit option or committing money to expanding the existing public options. It might not have mattered if they were en route to a 5th 'ship next year, but in what will be a more sterile atmosphere than they assumed, what they've done to Oakland is going to finally get some attention.
They tried to build the arena in a much more convenient SF location (for transit) but it got shut down. Shockingly, I don't think the warriors care a lick about their security guards.
Also the Curry's are moving to SF from the East Bay because of the commute (and they have sticker shock lol): https://m.sfgate.com/warriors/article/Steph-Curry-Ayesha-moving-San-Francisco-home-price-13754725.php
That's funny, he joked about taking a helicopter but if he really digs his existing place, he should just figure out how to use his wealth to make getting to work from his place more convenient than it's looking now.
I'm sure the Warriors don't care about the security guards but will care about the backlash they might get next season when the new place isn't as rocking as they anticipated.
Theoretically, if GSW had stayed in Oakland, would SF itself have supported its own team, on at least a Clippers level relative to the Lakers?