Sorry to burst your bubble, but Google and IBM are both Samba users. As is Nutanix, Panzura and a whole host of on-prem -> Cloud gateway companies.
You have a strange definition of poor :-).
You have a strange definition of poor :-).
https://sniasdc19.pathable.com/meetings?query=samba&with[lab...
If Samba is terrible and only used by poor people, why are there so many Samba related talks at SDC ?
Big companies have the resources to do many weird things but it would still strike me as odd to be running Samba DS in production.
How far along is the directory server these days in terms of stability and features?
There are also some large cloud-based companies using it (and I mean other than the Amazon "Simple AD" solution that they never really promoted much - my suspicion was they did that to get a better price from Microsoft :-).
Hang out on the samba-technical@lists.samba.org list and you'll find around 70-80% of the questions are from Samba-AD-DC users - the fileserver is considered a somewhat solved problem these days.
Look at the email domains to get an idea of who is using it and for what.
It's just easier to keep using SMB3 :-).
Our uses for it ain't really all that significant, though; it's mostly for user management (and only for some things, like desktop logins, SMB shares, and our client VPN auth).