Don't defend them then. Do you believe the same should be true of your operating system? If not, then it shouldn't be true of the browser either.

> Do you believe the same should be true of your operating system?

Yes, and I have actually started virtualizing everything inside my computer because of that belief. I don't want random software touching my trusted host.

"Random software" is currently defined as anything outside the official repositories of my Linux distribution of choice. I don't want to share a home directory with such things. I don't want to share a user and its permissions, I don't even want to share a kernel with them.