When I read "In addition, threading in Python performs poorly due to GIL." and then just leaving it at that, I wasn't expecting any sort of performance or resource usage investigation.
When I read "I would seriously consider using Go for writing server side of web applications as it provides a right balance between speed and memory efficiency of the running code", I was expecting at least some number to back it up.
Agreed. If we want to nitpick further regarding the GIL - Python boosters could state that the GIL is just a implementation detail of cPython that is not a problem in other implementations, like Jython or IronPython.