Are you saying that in the general case if you send someone a written offer for something and then don't honour it, you are in breach of contract?
That doesn't sound right to me.
A written offer is not the same thing as a contract.
Offer and acceptance are part of how contracts are formed. There is no contract without there first being an offer.
If you accept someones offer, provided it meets the rest of the criteria for a valid contract - congratulations you now have a contract. If the any party violates it, yes this is a breach of contract.
> A written offer is not the same thing as a contract.
An offer is a precondition and component of a contract
The customer spends money to buy the product along with the source code offered. It's part of the transaction. Not honoring part of the transaction is a breach of contract.
Maybe it’s not technically “breach of contract”, and an offer might or might not be a contract. But if you don’t honor an offer you made, you must surely be guilty of something. Otherwise, all offers would be meaningless and worth nothing.
And what are the damages?
I think they're just saying the GPL doesn't really cover consumer/distributor (dis)agreements, it only covers copyright. While the spirit of the GPL is user-first, it still has to be realized within the confines of copyright law. Even though many people might conflate the spiritual goal and the legal agreement, it doesn't grant "users" any extraordinary legal powers.
It's not illegal to not honor written offers, it's illegal to distribute copyrighted material in violation of it's license.
The written offer is part of the licence, as is the need to respond to that offer with the source code offered. It is all part of the same agreement.
A written offer on its own would not normally be directly enforceable in many (most?) jurisdictions, for the same sort of reason that retailers can't be held to incorrectly published prices (in the UK at least, a displayed price is an “invitation to tender”, not a contract or other promise) except where other laws/regulations (anti bait&switch rules for instance), or the desire to avoid fighting in the court of public opinion, come into effect.
But in this instance, the written offer and the response to that offer are part of the wider licence that has been agreed to.