> The industry standards need to move at a faster pace

Agree entirely, however the motivations of some are to constrain change, and concensus is typically hard to acheive. An industry standards body also often finds itself trapped between the competing interests of its members and ... well I could go on, but we all understand the problem.

My motivation is to encourage the standards body to allow for private extensions in schemata. There is no reason why a standards body needs or should be in the middle of trading partner agreements which manifest themselves in data exchanges private to those individual organisations. The concern often expressed is that private extension degenerates the standard, but the reality is, without the ability to accomodate change (both breaking an non breaking) and allowing participants to adopt change at a time of their own choosing, then a standard has no future. Natural market pressures will drive adoption. Extensibility (call it forwards/backwards compatibility if you like) is certainly part of the solution, and, as you point out, careful selction of what should be mandatory and optional, and implementation of various validation schemes that support the level of compatibility/tolerance that an individual or pair of trading partners require, and .... well you get the picture.