2 things I'd like to point out in response to the op...

1. The "average" hobbyist user isn't nessessarily using the most recent version of the programs as their systems may not be capable of meeting the system specs required for said new versions (not everyone can afford to upgrade to the latest computer system every year or two to support the upgraded software)... It's also entirely possible that users may simply choose to stay with one version of a program or another because they see no need to upgrade or because they are comfortable with the versions they are using...

In order to ensure that the widest market audience is supported it is often nessessary to continue to provide older file formats and file structures that will still run in older versions of the programs we use. As the older versions fade out (which happens over time when the average user base is finally able to upgrade to newer hardware and software) the older file structures and formats will fade out to be replaced with newer ones, how-ever this also means that even newer versions of file types and structures will probably be in use by the leading edge users.

As a vendor it is nessessary to ensure wide base compatibility to maximize potential income and sales... and not terribly feasible to try and keep up with the constant shifts in customer preference and software. It is rather more important to keep up with the needs of the "average" users needs than to try and keep up with the few "leading edge" users.

Also... it's simply not possible to meet the demands and preferences of each and every customer, as each one wants something different. Sure, vendors could make a model that would work in every conceivable program and include every possible permutation of customer preferences, but you certainly wouldn't be paying the low prices that most vendors charge. More likely any attempt to do so would drive the price so high that no hobbyist user could afford either the content or the programs!

 

2. The only difference between a pz2 materials pose, and an mc6 materials file is the file extension and a single line of code in the text file... both of which can be easily changed (there are a number of simple tuts on how to convert back and forth between pz2 and mc6).

Anyone that can change a file extension and use a text editor can change one to the other in about 2 seconds. Of course it's not nessessary to change anything as pz2 mat poses will load just fine from either the "Poses" library, or the "Materials" library... it's simply a matter of organizing the files in your runtimes...