Be that as it may, but I can also feel the pain of implementing an old-as-balls image standard which has lots of historical options which account for, let's say

Be that as it may, but I can also feel the pain of implementing an old-as-balls image standard which has lots of historical options which account for, let's say, 70% of the effort of implementing the full standard, but are only used in .5% of the images available "in the wild". If these parts are then left out of implementations, it's regrettable from an academic point of view, but still understandable...