Why do software companies think they always need to redesign programs and apps?

I realize that upgrades and fixing bugs keeps the industry humming and my sons in bread and butter. But so often companies come out with a totally different design or a new interface that end users do not want or have trouble adapting to. It’s not like they make more money by coming out with a new design.

I’m thinking specifically right now of Facebook’s “new Coke” that is being roundly disliked by all who have tried it. I had it on for about 30 minutes last night and reverted to the old version but that will be gone next month.

Why do they ram these changes down our throats?

By the way, this will be posted in General so off-topic comments like “Don’t use Facebook” will be flagged.