Regarding the claim ... > Data Structures expose callers to recompilation and redeployment. Classes isolate callers from recompilation and redeployment.

... most projects (maybe all?) I've worked on in 20+ years deployed a full set of new bits upon release, rather than trying to differentiate at the level of which source code files were and were not touched.

So this strikes me as a carryover from many years ago when working on large C++ projects with slow compile times was even more painful than it is today.

Any counterpoints?