...I don't think so? Or at least, it's totally alien to me as someone who's spent ~6 years in SF tech.

1,200 $/mo is more than enough to get a room to yourself in the nice neighborhoods; admittedly, you'll need to put in the time on craigslist to find sublets, "interview" with potential roommates, etc. I can see if you're desperate to find a place in a hurry, an airBnB like this might make sense for a month, but more than that seems insane.

Getting scammed by false promises of equity riches is definitely a thing that happens to people, but it's far from the norm. Again, take a job like that if you need something right away, but spend your time hunting for something better, because the vast majority of programming jobs in SF are nothing like this.