Programmers love good code: good expressivity, good organization, ease of extensibility, maintainability, and so on. But we also like the code to be pretty, it makes the work more pleasant and enjoyable, but all this is probably not just for visually appealing reasons.
Is always nice to work with a style consistent code, it even makes it easier to navigate and read, our brains can dissect it more easily and our eyes can quickly jump to the right place. A pretty code transmits the idea that the people who wrote it do actually care about the program.
But there are some mundane reasons too… For lots of us an annoying voice in our heads is constantly telling us “you’re wasting storage space, you’re and idiot!” because some trailing white space or unnecessary blank lines are laying around in the code. Sure, those few extra bytes won’t hurt your 1+TB hard drive!, but for some of us it just feels wrong.