That being said, it is well known that Golang's present GC performs poorly. It presently fails to free memory in certain cases, and has pretty high overhead. There is work done on improving the GC to be fully concurrent, but that is still probably still 2-3 major versions away.
Actually, the Go team is making very good progress on all the prerequisites to real-time garbage collection. Who knows if they will manage to get all the way there, but I know there's been some discussion about it on the mailing list.
If you look at how fast the GC has improved over the years, it's kind of ridiculous that anyone bothered to criticize it at all, as if it was not really the temporary solution the devs said it was, and was in fact going to stay shitty forever.