What's wrong with older computers?

Let me start by saying I have been diving using dive computers for 21 years, and am asking to get others thoughts on the subject. My first dive computer was a Suunto SME/ML that still works after numerous battery changes and that I usualy take along in my BCD pocket as a spare, my current computer is an 7-8 years old hoseless unit that does everything I need, still I may replace it in a couple of years. With the exception of Nitrox, and assorted bells and whistles (back lights, computer interfaces, etc.), is there any reason you see why someone could not routinely use an older (up to 20+ year old) dive computer for routine recreational diving on Air. This is assuming that the computer was a quality unit when new, and not one of those few specific models prone to failure.

Ike

When I started diving a friend of mine passed me his Suunto Octopus II it had 986 in the dive history counter. He said this will get you started. I have since bought a new fangled super duper Cochrane. I still use the Octopus when I dive air...I just like the simplicity it feels like an old piece of clothing, it also is more conservative when compared to most computers.
I am interested to see the response to this thread. Maybe it is time to put it on a shelf?