I guess that's what I get for being so terse - I actually meant it as a counterexample. Windows is a good illustration of what happens when you avoid deprecatin

I guess that's what I get for being so terse - I actually meant it as a counterexample. Windows is a good illustration of what happens when you avoid deprecating older systems: you end up with multiple design philosophies and interfaces layered on top of each other, leading to a less cohesive user experience overall.