On balance, CAD has improved the industry for sure. But, because I'm old enough to yell at clouds, I would like to point out the flip side.
In manual drafting days, changes were hard, as you note. But because of that, there was a LOT more pre-planning, because once you start putting the Koh-I-Noor to mylar, changes were difficult. So you avoided them whenever possible. Architects had to sit down with owners and say, "look, past this point, you don't get to make changes, at least not for free."
Now, buildings are quite often designed-by-addenda. The due date is just a date. You get extra time to actually "finish" the job by issuing massive addendums prior to bid. And because of that, architects don't make owners sit down and tell them everything, so you'll get A/V or finishes or whatever really, really late in the design phase. "No problem, we'll fix it by addendum."
I am also a bit sad that drafting skills have died out somewhat. I've seen some really, really beautiful bluelines. I've heard of electrical engineers who would make smiley-faces with their homerun arrows. And the process of manual lettering is very zen, and teaches people spatial awareness like nothing else.
All that said, man alive, I love AutoCAD. Embedding Lisp in the program was amazing. The modern thing is now Revit, which has some good things going for it as well, but it is not (and may never be) anywhere near ACAD for a lot of work. RIP John.
AutoLISP was put in because it was a memory-safe interpreter. Allowing users to extend AutoCAD with C would have created a debugging nightmare. AutoLISP could detect its own errors without crashing AutoCAD. LISP was the only game in town back then for interpreters which could deal with variable-sized data.
AutoCAD users were not programmers. Computer knowledge was not widespread. Keeping users from losing their drawing files, a major long-term asset, was crucial to product acceptance.
There was a strong "don't screw up" ethos within Autodesk. Much of that came from the founders, who were mostly mainframe operating system programmers.
In manual drafting days, changes were hard, as you note. But because of that, there was a LOT more pre-planning, because once you start putting the Koh-I-Noor to mylar, changes were difficult. So you avoided them whenever possible. Architects had to sit down with owners and say, "look, past this point, you don't get to make changes, at least not for free."
Now, buildings are quite often designed-by-addenda. The due date is just a date. You get extra time to actually "finish" the job by issuing massive addendums prior to bid. And because of that, architects don't make owners sit down and tell them everything, so you'll get A/V or finishes or whatever really, really late in the design phase. "No problem, we'll fix it by addendum."
I am also a bit sad that drafting skills have died out somewhat. I've seen some really, really beautiful bluelines. I've heard of electrical engineers who would make smiley-faces with their homerun arrows. And the process of manual lettering is very zen, and teaches people spatial awareness like nothing else.
All that said, man alive, I love AutoCAD. Embedding Lisp in the program was amazing. The modern thing is now Revit, which has some good things going for it as well, but it is not (and may never be) anywhere near ACAD for a lot of work. RIP John.