a6k wrote:
As was pointed out by Burkphoto, if you are going to run an old version of any OS, Mac, Windows or etc., then disconnect it permanently from the internet.
That is the rational, reasonable, safe answer to "why change".
If you are running software that is no longer supported then disconnecting it from the internet will prevent potential malware from getting on the computer. Older software is fine so long as it is still supported.