I'm not sure what you mean. Evidence indicates that code attracts more code, and big elements are frequently changed.

They grow. They change. But they can't be killed or conquered.

Not clear in my head either, but I just experienced the value of heavy structures at times.

I don't find the analogy working for software (a large structure is hard to change).

Software is always easy to alter, hack in some code here and there, move some functions around, add and rename files. The larger the software the more places to make changes.

It's unlike a physical structure where a 1000 tons wall really can't be moved.

informational mass (complexity) is hard to change in a way

you can always delete for free but there's no system anymore, and if you change randomly the system might fail

Funnily enough I usually experience the opposite. I've worked with very heavy systems and very light systems, and I always find more stability with the really light weight stuff. Obviously there are more bugs at first, but once you go through your first wave of code fixes I'm usually sitting pretty for awhile until I change more stuff.