I don't bother with blocking individual countries. Sure I could just block the whole 210.0.0.0/6 but with ipv6 it becomes untenable and not to mention that once a bad actor successfully attacks someone in your home country, then they can use that machine as a springboard to attack you - and how can you discern the difference anymore?
Just need to do the best I can to ensure people don't get in the usual ways...
I would have voted "because it's cool" but really it's because I have control of my software and my equipment. Education is part of the deal. Security and privacy is not guaranteed but it's under my control.
Definitely missing out on "better services" because large data models can do very good spam filtering which I don't get because I don't have access to other peoples' mail ... (which falls into privacy concerns... of other people...)