And I doubt generics make a significant difference in runtime but I don't have a CLR v1.1 around to test it out. For comparison, a C# hello world takes about 10ms longer than a C one (both compiled with optimizations; .NET 4.6 C# 6 / MSVC 19) on my i5 Broadwell laptop. Timing as measured by "time" in bash (~25ms vs ~35ms).
I'm guessing you're talking about JIT in general and of course have a point there. I doubt it's significant for any significant values of significant.
I remember the difference being a bit more than that, on the order of half a second in difference.. but that was around the .Net 1.0 timeframe.. I still used it for a lot of things because it didn't matter to me.. but a couple of things I wanted to use it for at the time was too much lag for starting an EXE and getting output from the command prompt.. running as a service was a different story.
A 1.2Ghz early Athlon was a lot slower than what we have today as well... even so, depending on what you need, even 10ms can make a difference.
In some cases, if you have long-lived services, then Java and .Net make sense... You can get farther with the code in place. If you are running one-off executable handlers, that need to start and finish quickly, then you probably would favor go.
It's entirely possible for different options to be part of a larger solution.. and while I agree, the lack of generics is truly painful... I remember C# before, and feel that Java's generics are a horrible implementation... I'd rather wait for a nice implementation just the same.