 It must be easy to change your area of study

This is a pre-requisite of Section "Students must have a flexible choice of what to learn".

If the choice of what to learn depend on a years long dependency graph of other obligations, which currently are the increasingly interlinked:you end up without much choice at all.

The lock-in periods must be much more fluid and shorter term than those, otherwise it makes the almost inevitable pivots to success impossible.

This is something that Ciro Santilli has heard from several people at the end of their undergrad/PhD degrees. Some online mentions: