> [git] was built for [...] much smaller projects,
It was built for the Linux kernel. There are larger projects than that but how many? Of course if you manage to make them switch to Diversion and get paid for that you could be well off even with a handful of customers.
About technical matters, as a company I'd be very at unease to have all my code only in the cloud on somebody's else servers. At least with git there are dozens, hundreds, thousands of copies of any repository around the company. If GitHub or AWS close our accounts we can keep going on and move somewhere else.