Like many large companies - manufacturers are slow to change. A dozen years or so ago it made lots of sense for them to "require" certain tools, applications, and processes.
Today, nearly all of them do allow some flexibility in terms of what tools their dealers us. But many still have an "approved list" of vendors. We for example have gone through many many manufacture "tests" over the years. Enforcing some basic standards still makes sense in most cases.
Unfortunately, because there are SO MANY choices for dealers these days, I totally understand why manufactures would want to try to help dealers avoid vendors that simply "don't get it." I use the word unfortunate because there are literally hundreds and hundreds of "providers" promising to be the next-best thing that simply don't deliver. I have fond memories of teaching a dealer what a browser was before I could sell them our products - difficult to imagine for the younger guys I bet.
Our industry has come along way and still has a long way to go. It's tough to say what the manufactures will-do in the future regarding technology but I look forward to being a part of the change - whatever they are.