Earlier quoted context omitted.
The current system screws over newcomers in favor of longtime residents. Rent control and Prop 13 mean that if you've been living in SF for a couple of decades, you're paying bargain-basement prices for either rent or property tax. Asking people to vote against their interests doesn't work very well.
It also screws over people making less than 100k who can't afford a 4k/mo 1br apartment.
If they're long-time residents, they're paying $800 a month for that exact same $4k/mo apartment.
You're basically asking the long-time residents to vote for measures that will detract from the San Francisco-ness of SF and won't benefit them at all. This is why the NIMBY groups are so powerful.
The only way that you're going to beat them is by getting enough newcomers who can overpower said NIMBY folks in municipal elections. That's going to take a long time to happen.