My initial reaction looking at this graph was that it couldn't be a supply/demand graph, because the two don't intersect. If you prefer a metaphor, Twu's previous tweet delivers: "It's as if new cars got so expensive that people who normally splurge on new cars decide to switch to buying used cars... and without customers, companies stopped making new cars, and before long, there's a shortage of any type of car. That's Bay Area housing."
TL;DR: it's a safeword to ensure a robot voice isn't impersonating you, probably a good idea.
Threads
• Thread detailing a proposal for the federal government to create a program to help conversion of offices to residential.