Pandas I'd definitely categorize as being niche :) A moderately-sized one, but still a niche. And there you use whatever performs the way you need it, yeah - there are special constraints on the system, and pandas is built around dealing with them.

Haha, that one hits close to home. Iirc Pandas was the author's first big project, and memory use is one of the key things he wants to improve if he gives it another go. It's still an impressive piece of software.