In the world of real users? You're probably the extreme minority.
Most people want convenience, and will trade almost anything for it. Especially if they don't realize they are trading something like "privacy" or "trackability" for convenience.
The way I use Chromium [0], is very convenient to me. The downsides are almost nonexistent, and the upsides are not just in privacy: it is convenient (albeit perhaps of questionable morality?) to not have to worry about newspaper article quotas; likewise with having more control over cookies and other browser data in the "simultaneous multiple sessions" model. For example having more than one user logged in to some Web site does not take any extra effort compared to just one user being logged in.
On the other hand there is a difference between "real users" and those willing to exploit the Unix programming environment/interface to its full potential, and that is required knowledge, or the willingness to get it. For example to use my script tb effectively one has to understand that "being logged in with a Web site" means temporarily storing appropriate data chunks gotten from the Web site (cookies) so that they are accessible to the browser and it could send them back to the server to authenticate.
For the vast majority of people who do not already have Unix skills (or whatever), it is convenient not to have to learn them.
For example, I set my Mom up with a Firefox configuration that doesn't remember anything when you close the window (basically incognito by default). She has used that configuration for years and never complained. In fact, she always compliments me for how safe and reliable I've made her browser. When she sees other people on other computers just load their logged-in websites without having to log in, she thinks they're totally unsafe and exposed.
She associates closing the window == back to safety, so whenever she ends up on a scary website or sees a scary popup, she just closes firefox and opens it back up again. It's wonderful. I didn't have to teach her about cookies or sessions or anything. All I had to teach her was that if she ever got into a situation where she didn't know what to do, just close the window and you're safe again.
Anyway, I feel pretty strongly that if browsers were incognito by default and you had to opt-in to persist sessions (e.g. whitelist cookies), general users would get used to it pretty quickly and end up thinking the time back before was a very unsafe place (like the free love era before the AIDS epidemic).
No, this is what indoctrinated "UX" people think.
I hear it every day from ordinary office workers how sick they are from dysfunctional, progressively dumbed down UIs.
Ask just how many people keep MS Office 2003 just because they can't use the "ribbon" UI.
Also, design is simplified because that strategy works. People want simple UIs, while business doesn't want to invest in design, costs of which rise exponentially unless you have talent both in development as well as management at work, or deal with too many unique support requests.