It isn't about being cheaper for themselves
Well ISPs in the US already get a subsidy to pay for them rolling out broadband to less well off areas. This whole article is about how they'd like to reduce the definition of 'broadband' to make it easier (and cheaper) for themselves.
Actually, this article was about a meeting with WISPA. WISPA is a trade organization of local independently owned ISPs that deliver services over license-free wireless. The problem is that license-free wireless does not support the speeds of "broadband" as currently defined, even though they supported broadband as it was defined when they first started. Most WISPA members don't currently get subsidies, so your premise is incorrect.
WISPA members' problem isn't that their networks are worse, it is that the definition of broadband changed. Since the definition changed, they are no longer eligible for the subsidies. Since they aren't eligible for the subsidies, their growth rate is slower and unserved areas still don't get any service.
The areas we are talking about here aren't cities and urban areas, they are small towns and farms out in rural America where the antennas go on top of tall buildings and grain silos. The networks are slow and fragile, but in many parts of the country they are the only thing short of satellite service or dialup for Internet access. Many of these areas don't even have reliable cellular service.
Part of their problem is they use obsolete technologies that were never originally intended for outdoor point-to-multipoint use, the other part of the problem is that the cost to change exceeds the price point that consumers will pay. In effect, they are the obsolete wagon makers being superseded by the automobile. In that sense they will die off by attrition on their own without outside life support, so the question then becomes should public money be used to support them?
If yes, then people complain about the subsidies, but if no then areas will continue to go unserved.
Any area in the United States that is currently unserved is because it isn't economically feasible to do so. Internet access is a commercial venture so the companies have to operate to make a profit, and they aren't going to willingly enter a market where they know that they are going to lose money. That's why you don't see cable companies or phone companies building in those areas.
Note that I use the term "unserved". Unserved and Underserved are two different things, and you cannot equate the two. Since the subsidies go for both unserved and underserved, the larger players are taking subsidies to build out in the "underserved" areas where they can make money, but not in the "unserved" areas where they cannot.
Quite frankly, none of the choices are a good ones. Either you put public money into a dead business model or citizens don't get any Internet access at all, and even if you spend the public money the citizens still don't get broadband. Is half a loaf better than none?
My hope is that newer technologies will evolve to fill this gap, but I've been waiting for decades. Technologies have improved, but they haven't outpaced the consumer demand in this area.
Let the downvotes begin by all of the people who are too ignorant to know that there are more flavors of wireless and more types networks than cellular.