I don't really mind revising short stories. Oh, sure, I like it better when they spring from the page, fully-formed, but revising a short story isn't that bad.
Partially, this is because my short stories tend to be short. The minimum word count required to use a story as part of a Clarion application portfolio is 2500 words. Nothing I've sold so far is that long. The longest story I have in circulation right now is 2800, and that's really long for me. So even if I have to completely gut the story during the revision process (and I did for that one), I'm not throwing out a lot, time-wise or text-wise.
But also, I don't mind revising short stories because I tend to use them as places to experiment. So I'll alternate between second person and tight third pov, or write an unreliable narrator, or use the rhythm of Anglo-Saxon alliterative poetry, just to see what will happen. And it's fine if the end result goes flat, or doesn't sell, because writing the story taught me something.
Revising a novel is different. Linger is approximately 80K words right now (actually, on the short side for a novel, and that's one of the things the revision is fixing.) As I cut text, I am very much aware of how much work went into writing the scene that I just gleefully slashed lines through. Sometimes, that's a very discouraging sensation.
Last night, I realized that the subplot that needed fixing was woven more tightly into the main thread of the story that I had let myself remember when I decided it needed changing. So I am, I suppose, not actually revising, but rewriting the last two-thirds of Linger. Not in the sense of, oh, hey, I just dumped 250 pages into the recycling, but there is definitely going to be a lot more new writing than I had bargained on.
This is actually not a discouraging sensation, but feels rather akin to having skidded to a stop right before plummeting off a cliff. Things could have gone badly. I have the chance to make sure they don't.