If you play a lot of SimCity on Windows 3.1, then you upgrade to Windows 95 and SimCity stops working, who are you going to blame?
And I say this as someone who remembers the binders full of CDROMs that arrived, so not just "download this iso" modern day conveniences
Now how do you get that fixed software to every user who bought a SimCity CD or floppies? Remember, most of your users don't have a modem and there is no widespread internet infrastructure at the time of the Windows 95 release.