The thing with tech companies is their desire for most of their employees to be in-house.
Causing a mass of people to arrive at a location that previously did not have that.
Over time, of course.
People who, due to the nature of their job and their employer, earn way more money than the average working person.
And when 10 people like this go for the 1 available house on the market, guess what happens? The price of the house goes up. Up to a point where only 1 of the bidder is willing to pay that price. Or rent.
Notice that I said "willing to pay" as opposed to "what that person can afford".
Supply and Demand is nice in theory, but really, pricing is more a game of "ask the maximum amount you can get away with".
And of course, owners of property in the same region can't let their property sit at a value much lower than the property around them. If the property around them can go for a certain amount, then so can they.
And this process repeats unendingly. Making it impossible for people with non-tech jobs to get affordable housing. And if not for the big tech company, it never would have happened.
So yeah, it is 100% correct to put the blame on tech companies. If not for them, this would not have occured in the first place.