moonsun :
And why should we change a perfectly fine running OS?
You are completely free to continue running XP. You will just need to be more careful about not clicking questionable links, opening files from questionable sources, visiting dodgy sites, etc.
What do shiny and expensive device manufacturers usually tell their consumer-grade device customers after ~5 years when their devices either stop working or do not have driver support for new OSes? "Sucks to be you, buy a newer model."
Support for older stuff inevitably ends. If you were 20 years old today and invented something, would you think it reasonable to be expected to support it in its original form for the rest of your life? Most likely not. If someone finds a bug in Foobar 5.3 and your app is up to Foobar 8.1, you would most likely tell them to upgrade to 8.1 because investing more time and resources in the 10 years old 5.3 build makes no sense unless you are still selling enough annual licenses to cover on-going maintenance costs but even then, there will be a day where enough people will have upgraded to newer versions where annual licenses for 5.3 won't be enough to cover its maintenance costs or where you will have so many newer version that also need maintenance that you will no longer be able to spare resources for 5.3 regardless of how much licensing revenue it may still generate.