Having a slow website can be bad for a number of reasons. Sites that take a long time to load are given less favorable treatment by Google and as a result, receive less visitors from search engines.The second reason, and perhaps the most important reason, is that slow WordPress sites are bad for your user experience. This can result in a high bounce rate.
If you want to block certain countries from accessing your web site, there are many workarounds. The most popular and worst method is blocking by IP ranges. But this isn’t a effective solution because of the IP range allocations changes day by day and its almost impossible to find IP range data base of a big country for example like China.