Do people do things for negative reasons?
I used to imagine they do. I used to think I did. But now as I have come to watch myself and others, I don't think that is the case.
What someone chooses to do, their choices may have negative consequences. It can be argued in many cases that people are a product of their conditioning - their own, environmental and parental, etc. So they don't really have a choice. But, (as far as I can tell,) everyone chooses an action (or lack of it) because of its positive aspects, not the negative ones.
Often the choice is not so wise, or the selection doesn't take crucial things into account that should have been obvious to the person. Even more commonly, the person feels as if they "must" make the choice for various justified points that they are aware are negative. Such as choosing between two evils, such as what we have to do so often when we vote. Sometimes people are aware of the negative aspects, but they decide the costs are "worth it," possibly because sometimes the costs are deferred until "later." Some people like to gamble and play the odds, imagining they won't be the one to suffer the common consequences.
I quipped lately, when in the presence of a friend of mine who is a confirmed drinker, (alcoholics go to meetings) that has more time than a smoker to change her ways, because drinkers live much longer than drinkers who smoke.
Most often, I think what happens when people make what later turns out to be a "negative" choice -- it's that their priorities changed somewhere along the line. They got trapped. Sometimes they forgot to consult all the priorities, or to even realize they might have had priorities at all.
It's as though, sometimes, we are a multitude of shifting priority. Not every priority is present at every moment. So it's possible to make a decision that caters and answers to one particular member of the multitude of priorities, and forget a crucial one that got left out. Guess this is where the ideas of the subconscious came from.
Some of the time, nobody can anticipate the sum total of how things will turn out. So it's not possible sometimes to know how a particular choice will affect things on down the line. You just have to find out, and change things as you go.