Actually, a lot of the computer industry is built upon "reverse engineering".
And the very same people who built it turned right around and started working hard to make sure nobody else could do the same thing to them, by way of things like EULAs prohibiting it and attempt to push through laws like UCITA. Depending on which state you live in, the very act of reverse engineering might run afoul of your state's laws.
Even at the federal level there are things like the DMCA's anti-circumvention provision, and some much scarier stuff that they're trying to sneak in the back door via international trade treaties.
If you're interested in copyright law and the perverse ways it's often abused to prevent competition, fair use, and reverse engineering, you should hit up
eff.org to keep tabs on the current state of the war against intellectual freedom and what initiatives are currently going on.
And definitely read the actual text of the library of congress' report on the abandoned games exception.
http://copyright.gov/1201/2015/fedreg-publicinspectionFR.pdfStarts at the bottom of page 54, it's barely over a page long and is quite easy to digest; no understanding of legalese required. Read the actual text and it will be clear that it's written in a way to specifically exclude exactly the kinds of fanciful scenarios that are being dreamed up in this thread.
Also, read the summary on page 1 and keep in mind the context of the exemption -- it only applies to the anti-circumvention clause about bypassing technical protection measures. It doesn't give free license to make copies.