Almost anything derogatory you could say about today's software design would be accurate.

It took 300 years to build and by the time it was 10% built, everyone knew it would be a total disaster. But by then the investment was so big they felt compelled to go on. Since its completion, it has cost a fortune to maintain and is still in danger of collapsing. There are at present no plans to replace it, since it was never really needed in the first place. I expect every installation has its own pet software which is analogous to the above.

As my friends will tell you, I have an very good memory. It just isn't very long.