This has been my experience both in the case of a bank (where technology is an operating overhead) but, surprisingly, also in a tech startup at the stage where it was maturing beyond 50 employees. Even more surprisingly, we are speaking of a tech startup where the CEO, CTO and most senior product manager are all engineers. But they got into those positions when the company was just a handful of people and seem to have forgotten about their roots. What is going on now is that there is little to no real carreer mobility for newly hired engineers, and the company now has more non-technical than technical people, who have built up a caste system where they keep engineers out of the decisions that matter.

I'm curious where you're located. This was exactly my experience in "tech" startups in NYC, but not my experience at all working in SF. This is a big part of the reason why I have zero interest in leaving SF for some upcoming tech city, as in my experience you are correct there is a tendency to push engineers away from any business decisions, but much less so in SF which has a culture that ties engineering to entrepreneurship more closely. One explanation I've noticed is that the VCs in the Bay Area are far more likely to have technical backgrounds, whereas in NYC the VC firms almost always have finance backgrounds, and that culture bubbles down.

You're quite right: I have had no direct contact with the SF / Bay Area, nor any companies based there. I've mostly been based in major European cities, and in some cases working within the European operations of U.S.-corporates (that weren't Bay Area startups). In a few cases I've worked remotely directly for U.S.-East Coast startups.

I think this is the answer. At investment banks (I interned at one once) the tech people were a cost center, not a profit one, and the power structure reflected that, whereas with many Silicon Valley type companies, it's the opposite. I guess this is what people refer to as having an "engineering-driven" culture.