This isn't a case of young whippersnappers not knowing what a cathedral looks like. This is a case of the system getting so large that the combinatorics are no

This isn't a case of young whippersnappers not knowing what a cathedral looks like. This is a case of the system getting so large that the combinatorics are no longer surmountable. If I'm just starting on a program, and I realize that I zigged where I should have zagged, I just go through a handful of small files and make them zag. I believe Knuth did the same thing and re-wrote tex after his first attempt. Once the system gets larger, updating every boundary and interface to something sane falls somewhere between costly and insane. Don't get me wrong, I'm all for a re-do, it's just that nobody in the private sector is going to foot that bill until we're in crisis mode, and the wizards who remember what the mistakes were aren't getting any younger...