It isn't scaling horizontally at all. You scale horizontally to increase your capacity, installing one antenna for every user has zero to do with capacity and everything to do with legality.

I maintain that having a multiple of identical components in a system that perform the same duty is horizontal scaling. There are many reasons to scale horizontally, and I'd say increasing capacity is exactly what Aero would be interested in, not to mention fault tolerance. My career is based on building distributed fault tolerant systems, which is potentially why I think I understand their approach differently than you do.

But yes, horizontally scaling systems comes at a cost, sometimes they are more inefficient, sometimes they cost more, but in the long run if it helps you meet the goals of the business it shouldn't be illegal.

Their approach was not to create a distributed fault tolerant system (but boy am I glad I'm talking to someone with such expertise with them) - it might have been a neat side effect of what they did, but it wasn't the reason for doing it.

They said themselves that the reason each user has an antenna is because it was what allowed them to legally operate. Their hardware setup was entirely based around a loophole in existing law. Ironically, it's awful horizontal scaling, too - if a single antenna breaks there is no backup, the user assigned to it loses their TV signal.

They give two antennas for each user (one for live stream and one for DVR). And since they were still adding new users, it is reasonable to think that they had, at any given time, more pairs of antennas than current customers. If one antenna failed, I imagine they had a backup one they could switch to.