@Anonymous @Graeme48
By law, burden cannot and should not be placed entirely on one party in any contractual agreement.
Hosts stood ready and willing to provide the service in question, as per their part of the agreement with their guests. It is no more their fault, than it is the fault of the guests, that the service they agreed to provide, was not/could not be availed of, due to circumstances beyond the control of both parties. Consequently, it is both unfair and unlawful that one party (hosts) should be/have been forced to assume 100% of the burden.
"It is trite law that it is, in any event, impossible to assign "the contract" as a whole, i.e. including both burden and benefit. The burden of a contract can never be assigned without the consent of the other party to the contract in which event such consent will give rise to a novation"
(Novation - the transfer of contractual obligations)
Also.
" Neither at law or in equity could the burden of a contract be shifted off the shoulders of a contractor on to those of another without the consent of the contractee.'"
Furthermore..
"The principle that the burden of a contract cannot be transferred so as to discharge the original contractor without the consent of the other party means that, as a general rule, the assignee of the benefit of a contract involving mutual rights and obligations does not acquire the assignor's contractual obligations"