"The time it takes to load the framework and compile the program are often much more than the time it takes to execute the program, and the runtime framework may use more resources than the program itself when running. Programs using such a framework sometimes have unacceptably long response times for simple tasks like pressing a button or moving the mouse."
When efficiency is important, the startup time of the VM hardly matters. Even if it would, the issue is not loading the Framework (class library) but JIT compilation. And, no, simple tasks like clicking a button will certainly not cause any observable delay due to the language.
(Of course, looping in that way is still inefficient when your program is written in C.)
Clicking a button shouldn't cause a noticeable delay on vaguely modern hardware, I agree.
It's a shame that nothing quite so comprehensive exists for IO, as network and storage accesses, patterns and quirks are often more of a bottleneck than CPU, for many applications.
