From the point of single node it would only mean that you lost some connections but you are able to quickly find replacements. At the end now, when you have your node and you are connected to 10 other nodes, you do not know if you are connected to Asia and Australia or to your neighbors on the next street
Each country have different IP address allocation, so you could make educated guess based on other node IP.
there is no criteria for nodes selection, is there?
It depends on which full node implementation you use. IIRC Bitcoin Core avoid make connection to multiple nodes with same IP block.