"Comprehensive Counter-Terrorism Act of 1991"
"Sponsor: Sen Biden, Joseph R., Jr. [DE] (introduced 1/24/1991)"
"Cosponsor: [...] Sen Reid, Harry [NV] - 1/30/1991"
"It is the sense of Congress that providers of electronic communications services and manufacturers of electronic communications service equipment shall ensure that communications systems permit the government to obtain the plain text contents of voice, data, and other communications when appropriately authorized by law."
What is specifically objectionable to you? The quote you provided seems to be the only substantive reference to electronic communication and extremely toothless/redundant. (wouldn't telcos be assumed to be compelled to release "lawful" requests by default?)
It's not about questioning the law, it's about uncovering the internal works of the law. My previous readings pointed to this bill as one of the earliest regulations that was used by everything in plain text. A nice way to describe backdoors without saying them explicitly, especially if the product claims to be secure from snooping. But what message does it send that the law orders you to screw your customers?
This specific bill might have died (I'm sure the patriot act superseded it), but every NSA-related revelation (and the FBI ones ~3 years ago) point in a direction that something similar is still in effect.
edit: link is not working, but search for the title, it will open up from something like this: http://thomas.loc.gov/cgi-bin/bdquery/z?d102:S266: