It's the (IMO faulty) theory that all regulations increase prices. Sort of like "if you require all houses to meet code, you can't have a market for very low quality houses that would decrease the prices of mid quality houses".

The problem with this theory, particularly in the case of an ISP, is you need an actual free and open market with a large amount of competition before it starts making any sense. When you talk about things like ISPs which are region locked and have low or even no competition then it's meaningless. A region locked ISP can (and will) charge pretty much any price the market will bear divorced from the actual cost of service.

Depending on how they treat oversubscription, Wireless ISP's cant really offer this speed reliably, so they would lose their subsidy.

So building housing in a remote area only served by a WISP gets more expensive.

In practice I don't think the FCC really thinks about oversubscription.