There's a lot of arrogance, much of it unjustified. I've seen a lot of corruption or incompetence (sometimes it's hard to tell the difference). There are grand visions that get pitched that are so out of touch -- I can't tell if we need "forward thinkers" to be dreaming of moon shots, or if they're just full on delusional. There can be a lot of backstabbing and politics within organizations. Sure, that all happens outside of SV too, but I've never experienced it quite on this scale.
That said, the Bay Area also attracts a specific type of person that can be really amazing to work with. People who are smart, want to change the world, and unbounded in how they approach problems. I've found periods of my time here to be really amazing-- working with smart and driven people, going to meetups to hear from developers building the packages that I use, and enjoying the culture scene in SF. Often, I've found that golden period to last for 6-18 months before the startup has layoffs, or a new "commercialization" officer comes in and makes things horrible, or we hire one too many Stanford MBAs.
So, for me, it's been an exhausting boom-bust cycle of working on amazing things, followed by the company growing toxic, then I leave and a few years later that company implodes in scandal. If you do that cycle enough times, you meet a core group of people that you can just follow around to different companies.
In the background, though, it's really difficult to afford to buy a house. Dating has been brutal because it feels like everyone is trying to "date up". Homelessness and other social justice issues pervade the Bay Area and seem to only be getting worse. Fire season is approaching 6 months long.
I love it here but, personally, I think I'm ready to switch back to being a tourist instead of a local.