absolutely. I'm an engine programmer and this has to be my train of thought, otherwise I'd be out of a job (you know, until the 11th hour where I break a lot of work just to get something out).
I'm not saving a few milliseconds on some feature that "only" takes 2 milliseconds because the game needs maximum performance. It's so when the director or designer comes up with some other crazy idea that they have more frame budget to try and fit it in. They may still not be able to, but I don't want my default answer to be "no, we can't spare the time" (not unless it's something absurd).
Others don't. Because the floor for performance tolerance is low enough you don't need to bother most of the time.
After all premature optimization is the root of all evil.
> After all premature optimization is the root of all evil.
This quote means not to optimize too early, not that you shouldn't optimize at all.
More than in other kinds of software, adding new "features" to games tends to slow the game down more (you're trying to do more in the time you have to render a frame). So often performance improvements are needed simply to make room for more "features".