I've been in SV for a decade now and I am not observing anything cult-like. I haven't worked for companies like Google or Facebook or any other giant behemoths, so no idea how things are there, but in other places it's pretty far from a cult where I am.
Of course, marketing sometimes goes a bit over the board, and each release of version 8.4 is the best thing that happened to humanity since v8.3 was released and before it's time to release v8.5. But that's kind of expected, nobody I know takes it as a literal truth.
And of course there are mission statements that talk about improving human condition and expanding horizons and saving the world. Sometimes it happens, at least to a measure, sometimes it doesn't, but that's not usually what you're thinking the whole day about, and even not something you think about every week or every month.
And of course (almost) each startup CEO thinks his (or her) startup is going to change the world, or at least some part of it. That's how you should think if you're getting into a startup, otherwise it's not worth the trouble, the stress and the extremely high chance of failure. Of course the CEO believes she (or he) found some special thing nobody thought of before and some unique vision nobody had before - otherwise how the startup could take off the ground at all?
And really, describing giving up free gym, yoga class and cafeteria as "something horrible happening to you"... I can't even find adequate words to describe how wrong this is.