What I'm saying is that a specific piece of software, left unchanged and unpatched, will get LESS secure as time goes by.
There is no argument for "it was always unsecure". Security is relative, and in the electronic world, it's relative to the amount of people who know how to exploit the security holes in the software. Back in 2001, without any service pack or patches, Windows XP was MORE SECURE than it is now, with the SP3 and all the patches.
And as a matter of fact, it was quite an improvement of its predecessors, even if it was always a joke, to our eyes of today.