AV has become full Stack, it has been becoming Full Stack for years. Any other industry that changes people adapt. The fact Crestron is embracing modernity is what sets them apart. I just can't fathom how a company keeping us with the most up to date tech is a bad thing to people. Also I didnt come from a web Design background, I just taught myself Frontend and Backend, their are thousands of free resources to do it with.? I can also tell you, Developers are starting to come into the AV world, since the 2 are becoming more and more aligned, so you will eventually be competing with fully trained Dev's for employment in the AV Market.
I can list resources for anyone wanting to learn more skills to help stay competitive in the coming years in an ever rough job market.