I think the rent issue is definitely real, but isn't the fault of techies. It's the fault of several interacting factors:
(1) Anti-development mentality on the part of city councils, zoning boards, etc.
(2) Geographic containment of the area.
(3) Shitty public transit and overcrowded roads.
(4) Foreign investors driving up the price of RE.
... in roughly that order.
#1 is largely the fault of this same stereotypical bunch of braindead trustafarian hippies, since they tend to oppose building pretty much anything because it destroys the Earth, man. In so doing they play their role in the gentrification cycle, constraining supply to drive up rents and drive out the genuinely underprivileged.
As I said elsewhere: fuck these people.