It keeps running
Cause it would cost to much to replace it.
I worked for a company that had a couple VAX's and Alpha's still running up until 2012. I think they finally got off of them right after I left because it cost a ton of money to fully replace them. Some places do not have that kind of money so it continues to live as long as you can find parts on Ebay and the sorts.
Biting the hand that feeds IT
