Decompilation / reverse engineering is very different from "transcribing" a play. Transcribing a play, you would get back an almost exact copy of the source material, whereas decompiling is more akin to taking a car and measuring all the bits of it. You would certainly not get the original drawings or CAD files back out of it. You do not decompile "source code", but machine code, and the source code you get back is not a recreation of the original copyrighted code, but the decompiler's analysis of the machine instructions, stripped of the original design and intent (the creative work part which makes source code copyrightable in the first place).
Measurements (or information) in general is not copyrightable, despite what IP protectionism claims, and in this analogy the machine code is much closer to the mechanical pieces of the car that make it work than the original designs. Either way, the fair use / reverse engineering provisions already create an exemption.
The questions is wether there are enough legal loopholes to squash these generally allowed uses through some other parts of the law or licensing terms, eg. by claiming that some IP (patents, trade secrets) are infringed some other way by publishing the reverse engineered code.