I have an aversion to proof, other than legal (50%+ civil, beyond a reasonable doubt criminal), mathematical (what makes mathematicians happy) and baking (whatever makes bakers happy), science post Popper doesn't really do proof.This observation doesn't prove BPS ideas right, it proves them wrong. I didn't learn to feel bad about an activity in the past, with the feeling inappropriately persisting and keeping me from doing things, and therefore causing an impairment in ability to carry out activities.
It shows that I do activities despite knowing they could or will be unpleasant (because I actually feel good about doing the activity initially), and keep doing the activity until the point where it's just too much to bear. And the negative feelings about it disappear quickly anyway with rest (within hours or days). In the BPS view these feelings would have to persist for years and decades in order to cause long term disability, like a kind of traumatic experience that we can't leave behind. Nothing of the sort is happening here.
This feeling is more like a kind of pain. It shows that activity gradually increases this kind of pain. This is one of the causes of impairment.
Also I'd prefer not to give the psychological hypotheses of ME/CFS pathology the credence that they are worthy of being countered - they either meet a scientific standard, i.e they are stated so as to be falsifiable or they fall, no further consideration necessary. As far as I'm aware there is no psychological hypotheses of ME/CFS pathology that meets a test of falsifiablity, let alone one that has been put to any meaningful examination, they really are not worth mentioning.
I do find the notion of aversion as it relates of ME/CFS a bit difficult to get to grips with. Even if we take the aversive stimulus to be something with physical reality, rather than say a notion of that reality, the aversive response is behavioural. Nobody thinks that having an aversion to putting your hand in a fire is unsound, yet athletes, performance artists and construction workers all go through apprenticeships that involve getting past common aversions to pain, discomfort and fatigue. Aversive behaviour isn't an absolute, something which the deconditioning proponents rely on, their argument was always that activity intollerance in ME/CFS was a mislearned behaviour that had to be adjusted by emulating the 'push on through' behaviour of athletes, performance artists and construction workers.
It could be argued that having an aversion to 'pushing on through' is a beneficial learned response in ME/CFS patients but that seems an overly psychologised way of saying ME/CFS patients need to learn to avoid 'pushing on through' as that behaviour is not appropriate to their health status.
From my own experience rather than aversion I think I'd talk about cognitively enforced activity halting, something which happens not so much from physical exhaustion but an inability to continue concentrating on a single narrow task - I wouldn't make a direct link but the attention deficit of ADHD offers a descriptive parallel.