I will reward people who post only pictures but just like in instagram I expect to know at least something about it. I think instagram picture only posts suffer just the same. But I don't expect people to write long blog posts like me. And I will reward so yes the answer is they not only will start but they have... because my vote counts.

I think it's an ok space for steemit to be in challenging the simpler posts like FB/instagram. (not 100% certain but seems ok)

I know some people want it to challenge Medium or traditional blogs. But I think communities will take it the other direction towards smaller content even more.

But that being said longer more thought out content will just get rewarded more.