Microsoft supporting something is pretty meaningless. I can only think of a few instances where an update actually fixed something - more often than not it has deleterious side effects. Support is an issue in enterprise environments but companies have to pay big bucks on support agreements - $100K a year for a system I worked on.
Arbitrarily changing the user interface with no recourse is a terrible way to treat customers. Also, it's pretty lame when a third party can easily add the feature back. I use Classic Shell and Classic Menu for Office so I can have the user interface I am comfortable with. Ironically, the changes made do not actually fix the shortcomings of prior versions - they just force users to access the mediocre features in a different way.
Backward compatibility is a noble cause. Like still being able to use conventional engines with command control systems. Any excuse that it is difficult is a cop out.