> The reason software developers rarely look at assembly code is that compilers (and emulators and VMs) are able to precisely preserve the semantics of the original program.

'Precisely' is doing a lot of work here. Depending on your language some things might be preserved and some not. Eg if you write stuff in Haskell, you don't really preserve much of anything about memory usage, you leave that to the runtime system to figure out, and exactly how the GC works isn't really specified in the language standard.