> The desiderata listed above are primarily concerned with lowering the "recurring costs", but the "one-time costs" are also a significant consideration if one is only using the mathematics from the given field X on a casual basis rather than a full-time one.

I think this is important and applies well to programming languages. Many programming techniques and styles can be extremely powerful when continuously working in the area whereas just jumping in they can be totally maddening. Sometimes this sort of thing builds up a cognitive wall to newcomers. It has its uses, but it's frustrating when you're one of those casual users having to deal with the clever ideas in the codebase.