Psychological reactance is the effect of irrational choice for freedom - we choose to go for a greater loss just because we like to make the bad decision for ourselves. What is the advantage behind that?
Too lazy to paraphrase right now, so quoting from a newsletter
Brehm [the guy how introduced the notion Psychological Reactance--my note] has made but one remark about why people seem to behave as his theory describes. He wrote that the reactance-emotion may have “survival-value” (Brehm 1966, p. 1-2). This explanation seems quite plausible. People and other organisms who are frequently in situations in which they can choose between different behavior alternatives are likely to have evolved a capacity for choosing what is most often best for their fitness. Moreover, creating, defending and restoring situations in which the individual is free to make a choice may in itself enhance fitness. Therefore, natural selection probably favored individuals who not only perceive when their freedom is threatened, but also act so as to defend that freedom. Brehm has described the psychological mechanism by which people (and probably many other species) are motivated to defend their freedom. That is, the attractiveness of behaviors varies with the freedom an individual perceives to possess.
As with most evolutionary hypotheses of behavior, it's probably hard to test.
I tried to find papers on animal models of reactance, but (unlike say for learned helplessness) there don't seem to be any. A recent review doesn't mention any such models either. It does however say some things that contradict your assumption that's just a negative outcome:
reactance can produce both undesirable and desirable outcomes. It has been found, for example, that the experience of reactance can elicit heightened achievement motivation (Steindl & Jonas, 2014). Recent studies have also shown that the experience of reactance can be associated not just with negative feelings, such as anger, but also with activating positive affect, such as feeling strong and determined (Steindl, Jonas, et al., 2015). We invite future research to investigate the desirable motivational side of reactance in order to make use of its energizing probabilities.