I wouldn't make the "let the landlord make more money" argument, I would be making the "rent control is a significant distortion of the market which hurts both renters and tenants in the long run" argument. Housing absolutely is a social priority, and while rent control is definitely a well intentioned attempted and addressing the issue, a more effective approach would be to build more - not restrict the price signalling mechanism.
Vacancy decontrol = new construction can have whatever rent they want. So preventing a landlord from screwing over the current tenant does not prevent housing from meeting demand.
New construction does face many other issues, though. NIMBY's, parking regulations, zoning, etc.
I am in a rent controlled apartment. I have been in this apartment for 4.5 years.
I full-throatedly support new, dense residential construction sufficient to meet SF's current and future housing demands. This will continue to be my position for the forseeable future.
For those folks who are concerned about new construction destroying their rent-controlled units, Sangiacomo and his tenants worked out a really good plan: https://news.ycombinator.com/item?id=9209304
