This is sad, but my point still holds. Perhaps being honest with oneself about real tasks that need to be done will help. Planning the architecture/feature, doing proof of concept etc. are all valid tasks even if they don't bring immediate business values. If you claim that you can only do business features without doing any exploratory work then you are effectively claiming to have an oracle giving you perfect solutions out of the blue. In which case you should stop whatever you are trying to do and start selling the services of your oracle.

We always do a brainstorming before implementing any serious feature / change. Once we have the initial design business gets involved (if we can get their attention...). The results usually works without needing any drastic changes, which is still better than no planning at all. It does require involvement from a number of parties though.

Even code have bugs so it's not perfect. Your design can incorporate high level algorithm to be implemented, ins/outs, or whatever else high level constraints are most applicable to your domain.

See my other comment regarding oracle: https://news.ycombinator.com/item?id=12249897

Yep. And then at the third sprint into this path you realize that the way the backend has been built during the first two sprints makes it impossible to deliver some essential or just very desirable feature that nobody took in consideration because it was outside the scope of the first two sprints. Seen it happen multiple times.

I disagree. This is how you end up with messy code that needs constant refactoring. Making time to come up with a composable design shouldn't be that difficult. It usually isn't.