I grew up farming and ranching and I agree with all you stated except for subsidized farming. If a crop is crap then plant something else. If everyone forgoes crap this year then demand will be higher next year and planting it may be worthwhile again. Crop rotation is usually considered a good thing. Government need not be involved.
The successful farmers I know have planted what would sell and usually had buyers before they planted. Sure we all planted some speculation crops, but they paid for new toys - or not.