Appreciating delight (for it's own sake) in software design I'd consider a core trait of (old-school?) Apple fans. E.g., lamenting the decline of whimsy in the post-Jobs era.
I don't know of a canonical piece that summarizes this idea, but it's referenced a bit in this short piece https://daringfireball.net/linked/2024/12/05/festivitas
I think there's truth to it being relatively niche, appreciating delight that is, but it's certainly not confined just to designers. E.g., like I'm saying here, a core trait of Apple fans is appreciating these kinds of details.
I absolutely do believe that software can be delightful. Linear comes to mind as an example - there are lots of little nuances to their interactions and it just feels so good to use.