When I upgrade customers from vertical application version X to version Y, they don't have to relearn the application. Even if I rewrite my app from VFP to WinForms, the look and feel and the flow of the application will be the same. So that people can continue doing their job without weeks or months (as is the case in changing development platform) to relearn. So your logic, IMHO, does not apply here.

You may think they don't have to relearn something, but they may not always see it that way. If it were true, why do vendors of vertical market apps (or really any type of app) often have this challenge?

Again IMHO M$ is becoming the company (in terms of their development platforms) of a few instead of many. With every new technology they lose a big chunk of the development community, either staying with previous technology or moving to something different.

If MS stayed with previous technology (in instances where not doing so caused some pain), many of the things they now offer today wouldn't be possible. We see that even in .NET - there were compatibility issues going from 1.1 to 2.0 - painful to some, but in the long run probably necessary.

Again, disagree. Response to the changes with new technologies is not as fast. I know you will disagree because you are a guru; that is, you are a minority who is capable of keeping up and being productive.

To be honest - I don't consider myself a guru. I also don't consider myself any smarter (or less smart) than most developers. While I've lobbied for change from MS, I also accept that things evolve and change, and that for new enhacements to occur, it sometimes means issues along the way. But in the entire development world, I don't know if I see that as the minority.