As a slightly above average dev in London (and I mean it), I feel that for many big companies the interview process always achieve on thing: to avoid hiring anyone who could really transform it for the better.
That is because in a large company you are hired to support the fiefdom of a manager that wants to claw to the top in the existing structure, not 'transform it for the better'.
IDK, I'm an extrovert and a senior developer, I've had mostly positive experiences with interviews, but I think you have to give people the hope that you're the person that is going to be able to make things better.
I think except in the worst circumstances, people can be worked with positively and if you bring a certain energy to the workplace you can bring people around to your way of thinking and bring out their passion.
Some people will dead weight no matter what, but they can be identified and let go.
In a big company, "transforming it for the better" is not a thing that one hire can do until years have passed. Sometimes it takes an entire career! So, at a big company interview, revolutionary attitudes are going to be known to be a pain in the ass. Not thought, known. A desire to fuck shit up "from the inside" grows to be less of a positive trait the larger and more inertial a company is.