@macfan I would posit a few reasons:
- The requisite expertise to do things right requires knowledgeable care and feeding.
- Acquiring said knowledge requires a substantial investment of time and energy.
- Ditto monitoring, maintenance, customer support, and all the other things that go into hosting anything well.
- Said investments take time away from other things, among which include earning income from other means.
- Life is expensive. People need to eat, feed their families, etc. NodeBB staff are no exception.
NodeBB itself, is free. Real Free and Open Source Software, a.k.a. "ROSS", and not some crippled, dual licensed bullshit that has become all to common in the "FOSS" sector over the past decade or two. Hence, you are able to self host the real deal for the price of a fairly minimally provisioned virtual machine at your provider of choice. If you lack the requisite knowledge to do so, then you have a choice before you: Either invest the time to learn such knowledge and skills or pay somebody else who has. NodeBB has pretty darn good documentation and exemplary community support here from both the larger community and NodeBB staff.
Blah, blah, blah, blah, blah.... In summary, I am reminded of one of the key Laws of Ecology: "There is no such thing as a free lunch."
Good luck!