On the one hand, I am reluctant to tell you my reasons for my choices because it winds up being an opportunity for people to just make this about me and ignore the wider issue that is under discussion. It makes it all too easy for people to act like "it is just one dumb writer making stupid choices" and then pick apart everything I say to justify their existing position. On the other hand, perhaps it will be illuminating, though a single comment here can't do justice to years of me trying to find a good answer.
I have considered other options, like trying to do an e-book or a subscription or something. I don't think that works.
One of my sites has information for homeless people. They can't afford to pay me. Another has information on alternative health approaches. Ads in that space are notoriously terrible in terms of touting unproven cures that can be downright dangerous. That site has no ads, in part because I have no desire to be inadvertently hawking colloidal silver.
These are problems I feel I have good solutions for. Everyone acts like they can't be solved. I think they can.
People are endlessly critical of the fact that you can't trust a person telling you do X for your health if they are selling X or you can't trust your doctor when he is in the pocket of big pharmacy, etc. But if you try to just put out information and that's it, you can't monetize it.
So we have this situation where serious problems are growing worse because you can't monetize an effective approach. People keep doing stuff that is making the problem worse because that is all the system supports.
And maybe someday I will cave and throw in the towel and stop doing something I believe in and go do something that pays better, thou it makes me feel I am selling my soul. But so far I am not there yet. I would still like to try to make a difference putting out independent information about things that work. But I also would like to stop living hand to mouth.