I agree with the conclusion (generics good) but the argument's not good. All your 25 year-old projects will have performance bottlenecks to the extent you don'

I agree with the conclusion (generics good) but the argument's not good. All your 25 year-old projects will have performance bottlenecks to the extent you don't look for and address them. The idea here that if you use generics your hot-path inner loops will be automatically optimized is nonsense. Yes, here and there you may get lucky -- the generics will exposes some code to an optimizer which will generate some great instructions without any extra work by you. But while shaving a few bottlenecks off it nice, if your goal is performance, the bulk of the work is the same: you'll still have to consistently profile and optimize your code.