Well, according to my therapist all brains, not just ADHD ones, do this - negative memories are evolutionarily more pertinent to survival (i.e. "this rotten/poisonous fruit made me sick" trumps "this fruit was really juicy").
On the other hand some people say ADHD can come with RSD or "reaction sensitivity dysphoria" (i.e. stronger reactions to negative feedback, thus salient negative memory etc.) - and sometimes that feels right to me, but the evidence is thin so far.
That is actually one of the major things that medication changes for me - things other than my current hyperfocus can be rewarding. Mind you I still suck at choosing the right activity, but at least I stick with whatever I'm doing.