I worked for a real estate company building an online real estate service since before the creation of VOW/IDX. Prior to that, the way we got access was through my boss's own real estate brokerage account with the state's main MLS. We expanded to support more MLS's in the area and each one was a huge pain in the ass. We had to have customers who were members of that MLS BEFORE they would give us access to their data. They would limit the data we had access to as much as they possibly could, and had absurd rules about what could/could not be displayed publicly, as well as privately when members of our customers' sites were logged in. It became much easier to get access to the data after the VOW/IDX implementations rolled out at each MLS.

but if you promote free and fair markets, you'd discourage/dismantle this kind of protectionism.