Redfin is a brokerage and thus has full access to the MLS. I'm not sure anyone can shut off Redfin's access so easily because of this?
(I work at Redfin).
Sparse coverage in sparsly populated locations.
For example, Redfin does not cover my home town, nor any of the Eastern CT cities I put in the search box, so for my parents selling their house, or anyone looking to buy in that area, it's not useful.
Maybe I was searching it wrong?
I think "spotty" is fair, though I root for your company and hope the coverage becomes universal.