To be somewhat fair, if 3rd party companies are selling hardware with pre-loaded pfSense, AS AN OFFICIAL pfSense firewall & router, they are probably loosing money. And possibly getting support calls from people that have no legal right to support, (of that type).
Imagine if a company started selling TrueNAS servers, both hardware & pre-loaded with software to small businesses. Possibly even implying support was available. Then, when those small business customers had problems, it might be a mess to because the small business might say: "Hey you, you wrote TrueNAS, I NEED support, I paid for support, so give it to me NOW!".