I would say at this point the reason for this is laziness on the part of manufacturers than a real compatibility need. The answer to incompatibility at this point is, upgrade (video player, etc.).
When considering the size of the user base that would truly be impacted by this there is a workaround – break the file up. Just as there are free splicing tools, there are free splitting tools (usually the same tool).
It's time we move forward past this archaic limitation, and inconvenience the tiny minority that still truly needs this for some reason (like ongoing support for FORTRAN source code in some military applications as an example).