Yes, but creativity needs structural boundaries in order to be channeled into practical use. A combination of structured ("focused") and unstructured time is probably ideal.

Structure need not be extrinsically imposed, though; it can be self-directed (otherwise known as discipline).

It's interesting that you put it that way, because I also feel discipline is overrated too. :-)

That said, I'm by far not saying that attention is unimportant. I'm just saying that it doesn't deserve the importance we assign it.

Also, I would like to see evidence that scheduling distractions like that still yields the same creativity benefit. Scheduling your distractions would seem to defeat the purpose, wouldn't it? Planning for unstructured time isn't the same as not paying attention. It's paying attention to something random, which isn't the same thing as not paying attention.

There is a simple way to summarize:

Attention/concentration strengthens neural pathways, and allows you to make further use of them. Lack of attention promotes creativity, i.e. creating NEW pathways and connections in the brain.

At least that's the way I think of it.