The 95% of business that you had experience with must have been from some bottom of the barrel places, intelectually-wise.
In the three companies I've worked for in the last 12 years (the last two counting > 10k employees), the "track changes" functionality, along with all related stuff (review comments, automated tracked change merging, accept/reject) was in active, constant use as an integrated part of work processes and culture. This extended to all of those companies' partners throughout any collaborative work on any set of documents.
That's not to say that the dreaded document versioning scheme using name suffixes (Document_2012-11-28.docx, etc.) wasn't in use - one practice doesn't exclude the other. It has been a common sight to see multiple document copies with different versions in their names cluttering a shared network drive, SVN directory (!) or a SharePoint document library, even when the underlying store was capable of versioning by itself. Still, lots of those versions were "draft" ones with tracked changes and comments inside them.