The Shuttle did pass human rating standards, and post-Challenger, it did have a (limited) crew escape capability. Pre- and post-Challenger, it had abort modes galore that were designed around human safety concerns.
Every bolt, every wire, every everything used on the Shuttle was controlled from the prior to pouring molten metal into a form the bolt or wire, and on up the manufacturing chain. This is part of what made the Shuttle so expensive to operate.
This also applies to lesser extent to commercial aircraft. Fasteners certified for use in aircraft cost a bunch of money. Oftentimes you can buy exactly the same bolt at your local hardware store, and all you will be missing is a hole in your wallet and a piece of paper that traces the pedigree of the bolt. MIL specs and NASA human rating specs make those FAA specs look like child's play.
The Shuttle did have a few CRIT-1A exceptions, the lack of a reliable launch escape system being one of them. Rules, even human safety rules, always have an out. Sometimes you might have to wait until the next ice age to get a waiver to a rule. Waivers are amazingly easy to get at other times, as was the case with regard to the a reliable launch escape system. The waiver rules are built into the human safety rating standards. Since the Shuttle had the requisite paperwork for those exceptions (with signoffs all the way to the top), it was human rated.