Do these contracts actually stand up in court if people sign without reading them and being given due consideration? Can’t find the link but I recall years ago some EULA provisions were found to be unreasonable and void by the courts (US I think).
In general the likelihood that the parties have read the contract doesn't have any bearing on the enforceability of it. But most such contracts are also contracts of adhesion (roughly speaking a take-it-or-leave-it offer), and there are special rules for the enforceability of contracts of adhesion. The principle is that they can't be too surprising or too unfair. There's a fair amount of case law about where that line is (which I mostly don't know).
Legally what's important is that you had the opportunity to read the contract before you agreed to it. In HN terms, as an example, you can't legally steal GPL'd code if you don't bother to cat LICENSE.md