Even in this case, the farmer who are farming on their own land are under no obligation to change their way of life or farming process. Even though we know that the methods they are using may be sub-optimal and a net-negative in the long run, we simply cannot make them change it, and certainly never by labelling them negative. We can make them see the benefits, or how it plays out in the long run and help them choose a better solution but ultimately, it's them doing the choosing.
At the end, if something is really really required, then it must be the Governments making regulation. This is how it generally works (I'm not saying I like it).
Can the bad farmers continue to farm debt (primarily)? Sure, but if they're doing it to themselves we shouldn't feel bad for them, or bail them out.
People only do what a) They are taught in the first place (programming classes, reliable blogs etc.), b) Their work environment imposes on them (organizations having coding practices or standards), c) They, through some personal experiences, find out that it makes their job easier down the line, or d) It is the right thing to do.
Expecting everyone to follow (d) is out of the question and in my experience all "good" work happens via (b) i.e. rules, regulations and standards that have been enforced. If some sub-optimal choice minimizes effort while maximizing rewards, then that is not sub-optimal, at least for the individual, even though it clearly could be a sub-optimal for the collective.
Crops prices have priced in the increased fertilizer cost already, so it is what it is. We're used to it.
If you want to see a profitable, productive mid sized farm, check out Polyface. Joel makes a good living while treating his land and animals well.
I'd argue that our mega-ag model is a big part of the problem, it's given us stupidly cheap corn/soy while causing a lot of health and pollution problems, and basically ruining farming as an actual profession.
The economics of farming are all fucked up, because our current farming practices have a lot of externalities that aren't priced into conventional produce, and producers who try to improve things to remove these externalities either have to take a loss versus the producers who say "fuck the future, fuck everyone who isn't me" or create new markets for their goods (which is where the whole farmer's market movement and the local food guilt thing come from).