U.S. spectrumWhen Michael Marcus and others at the FCC created the "unlicensed bands," they had little idea about how it would go. Wi-Fi has been a major game changer but that wasn't clear at the beginning. It's yet one more example of what creativity makes possible. Today, we see some congestion in the "commons," as well as proposals to squat on a large share. We need some "rules of the road" to manage the congestion fairly and efficiently. But they need careful design to have minimal impact on innovation. 

Fred Goldstein reminds me that the band is used for more than Wi-Fi.

As we develop rules, we have to consider these interests as well. 

There are other users of the unlicensed bands, though, of which WISPs are the most visible, though public safety and private systems are also quite common.  These are basically unlicensed microwave, not WiFi, even if they are based on WiFi chipsets using variant protocols.  These are used in both point-to-point and point-to-multipoint modes. Your typical WISP has a PtP backhaul radio feeding PtMP access points that are shared among 10-40 subscribers, who can be up to 10 miles away. WiFi arbitration doesn't work over such distances. Vendors thus create proprietary arbitration schemes, like Ubiquiti's airMax and MikroTik's Nstreme.  Some also use GPS synchronization so that multiple radios on a site (e.g., sectors and backhauls) transmit and receive at the same time, to avoid mutual interference, and to control end to end latency.
These systems use directional antennas, often with high forward gain, at both ends, which both maximizes range and minimizes interactions in other directions.  So they rarely conflict with actual WiFi systems. LAA, like Cable WiFi, would just add to the background din that potentially impairs their performance. 
Many problems to solve and we need the best ideas.