Why is wont facebook develop a window base application ?

[Ekim]

I always ask myself this question over
and over again. I know facebook is a
non commercial site making it returns
from the adds it serves. But still that
wouldn't stop them from developing a
window base application. This is where I am lost. If anyone have the
light, please enlighten me on what you
think is the cause of them still sticking
to the old fashion