realskiers

If we get in our time machines and go back to the time before manufacturers printed mounting points on their skis (to be aligned with a boot midsole mark), we would find that most skis of that era were very similar in geometry.  Today's more complex geometries utilizing multiple radii sidecuts were unheard of then (and we're not even discussing the advent of rocker/rise into the designs).  Skis mostly differed in flex pattern and most manufacturers spent their time developing solutions for managing torsional rigidity.

With these older designs, CRS (Center of Running Surface) made sense as a mounting point reference and skiers generally had their BoF positioned over the CRS by the shop doing their mount.  By positioning the BoF over the CRS, the skier's CoM and pressure distribution across the ski length worked very well for providing a satisfactory ski experience.  Unfortunately the shops complained that the process was time consuming and error prone and the industry decided to move toward a simpler mounting solution that was less error prone, but also no longer customized per individual.

IMO, the main problem with using a boot midsole mark is that most skiers do not have boots with a tight enough fit where the boot midsole mark actually corresponds to the foot's midsole point.  Since your foot when buckled into a boot moves rearward, almost all skiers are already rear of the midsole just due to their boot fit.  Couple the rearward position of a foot in the boot with the fact that most manufacturers err on the side of a rearward mount point on skis (to cater to recreational intermediates who generally skid their tails rather than carve their skis) and you can see that the problem compounds itself.

I believe that using BoF over CRS still works fairly well for traditional camber standard sidecut skis.