Echoes of Alan Kay's recent comment on how software devs are way too concerned with the how the computer works to the detriment of what the software is supposed to do.
There's sort of a "Maslow's Hierarchy of User Needs" that exists in software though. So long as the user can do something, and their immediate needs are met, performance concerns are just a small annoyance. And generally they will continue to ask for more features rather than performance improvements as long as the app remains usable.