Do you actually use the feature much?

From my experience I want to pin tabs because I simply want a set of tab available for use that remain visible when I scroll through a lot of tab headers to the right.

It's very annoying to be on a pinned tab, navigate to even just another server on the same root domain, and suddenly be pushed to another (un-pinned) tab. Even if navigate to a totally different url, I do no want to be pushed to another tab.

The enforcement of the url remaining the same should be done by myself, not the browser trying to second-guess me.