You miss the point. It is absolutely true that making a living by writing FOSS is really hard, but it's not just about money. Monetizing out of personal data and advertising has never been profitable like today; Open Source is the only defense against abuse in that context. Look at what many popular closed operating systems and products, hardware included, became in the last 10 years or less: they stopped being tools in the hands of the user to morph into business platforms that mine users' data and/or bomb them with advertising. Many people probably would accept to live in a world in which every square meter is plastered with some ads and every move is analyzed to infer users habits and ultimately find what would be the easiest way to grab the most money from them, but I don't. All this privacy and security aside, which in some countries can make the difference between being poor and being poor and jailed or dead. FOSS is the last line of defense against that kind of abuse, being a bit extremist when dealing with abuses is a sign that someone, somewhere, understood what is going on.

BTW: if making money with FOSS is hard, it's not FOSS fault, but rather it shows how badly our economic system has failed.