Inglebyboro.
The article you refer to has never been interpreted as an obligation to interline you to your destination. They would appear to have complied by the regulation by offering either a refund, or a rerouting on their flights. Some airlines do not have interline agreements at all.
Although VS does have interline agreements with many of the US airlines these usually charge the rerouting airline the full economy fare for the sector concerned (i.e. not the walk-up price, but a very high price published for the purpose of ripping off interline carriers)
Before you give up on their SFO offer, have a look at what prices are available on a US carrier. Not the best, but it might not be as much as it seems. You could even try to reclaim the fare you pay from VS after the fact. If it's not unreasonable they might refund it, or offer you that amount as a credit on a future flight.