Moved here 6 months ago. Lot of what you read is hyperbole. Truth is always somewhere in the middle. Bay Area can be amazing or horrible depending on where you live, where you work and how much you earn. There are some areas where I don't want to go but there are a lot more areas that are thriving, full of friendly people with great communities.
Yes, it is expensive - that is very true. Yes, taxes are high. But despite those, there is no lack of people moving here so there must be something right, right?
I have lived in 6 states in the US and 5 countries globally including most that people throw out as alternatives to the Bay Area. In my experience, Bay Area has the highest concentration of smartest and open minded people that I have come across. You want to build something? Bay Area energizes you because everyone will be encouraging and ready to help. Weather is nice. There are plenty of gorgeous places to visit, within the area and even more with a short drive.
However, I'll repeat - it is expensive! This is the most expensive place I have lived. We are a dual income household and money is less important than it used to be so for us it is totally worth it. Some years ago, we probably couldn't afford to live here.
There are two kinds of people I am seeing moving to the Bay Area - 1) high earners that can afford it and 2) those early in their careers who don't mind living in a less than optimal situation and moving here gives them a wage bump .
By large, the people moving away are those with average to good incomes who have kids and can't afford the lifestyle that they want. In the end, it comes down to what you value more. In the Bay Area, one thing you do NOT get is value for money. Will we be here long term? Who know but right now, I am in love with this place.