Any builder will also sign a contract stating to such an effect, or at least verbally state as much and take them on trust. It's certainly not some magical worldwide automatic assumption. That's what "binds" them to rebuilds/repairs. No contract, no binding agreement. Depending on project type and size, a builder may or may not add that stipulation to their contract. However a smart builder that wants to stay in business tomorrow, will price accordingly with that stipulation in mind.
Also, people get their panties in a twist over contracts. "But you signed the contract, you have to do it!!!!" Yes they do, but a contract is only good if it's followed. If someone chooses not to follow it, the only recourse is taking them to court.
Now slightly off topic but that's why imho trust >> contracts. Trust is "free" but hard to obtain, little nebulous but it's also far more reliable. Drafting a contract is easy and unambiguous (assuming the work is specified in there) but enforcing it can often be prohibitively expensive from both time and money. Dealing with bonded contractors can remove some of the burden because you have a small "guarantee" that someone else will do it if they don't.
Short answer: it doesn't apply to you unless you agreed to it upfront. So, the analogy is working off of fictitious assumptions.