We used them in an AT&T Labs research environment. The intent was less to prevent users from selfishly grabbing (then semi-precious) disk space but to prevent accidents from adversely affecting the user community at large. If you knew you were going to need honking amounts of disk, the sysadmins would raise the quota (probably on a partition dedicated to such activities).

On Thu, May 30, 2019 at 10:40 AM Theodore Ts'o <tytso@mit.edu> wrote:
On Thu, May 30, 2019 at 06:49:05AM -0700, David wrote:
> I think it was BSD 4.1 that added quotas to the disk system, and I
> was just wondering if anyone ever used them, in academia or
> industry. As a user and an admin I never used this and, while I
> thought it was interesting, just figured that the users would sort
> it out amongst themselves. Which they mostly did.
>
> So, anyone ever use this feature?

Back when MIT Project Athena was using Vax/750's as time sharing
machines (before the advent of the MicroVax II workstations and AFS),
students were assigned to a Vax 750, and were given a quota of I think
a megabyte, at least initially.  It could be increased by applying to
the user accounts office.  Given that there were roughly 4,000
undergraduates sharing 5 or 6 Vax/750's, it was somewhat understandable...

                                            - Ted