instability in Berkeley versus AT&T releases

[John Gilmore]

Ron Heiby at ihnp4!cuae2!heiby responded to a user's question "why doesn't
AT&T distribute [possibly optional] Berkeley enhancements, I hear they
use them in house anyway" with:
>                                     As to any other BSD developments:  They
> are all known of and looked at by AT&T developers.  Some appear in System V,
> like "cat -v" and "ls -RadCxmnlogrtyucpFbqisf" and "mailx" (alias Mail).  The
> thing to remember is that Berkeley is (supposed to be) in the education
> business.  They do a good job by letting students experiment.  AT&T is in the
> stable computing environment business.  We do a good job by making darn sure
> that what we do doesn't break something (like a shell script or worse) and
> that we spend our efforts spending resources on the most important/needed
> enhancements first.

By implication that puts all commercial vendors of 4.2BSD systems
in the "unstable computing environment business"?