You equated tranquil detachment with void of nirvana. That's a strawman as far as Buddhist monism and its "end-goal" as such is concerned. It's not a strawman, if you are concerned with de-facto practice. I said that you criticize Buddhist ideas (and Christian too, btw) on the basis of misguided practitioners. That's like criticizing and doubting shovel's usefulness because kids cannot use it properly.
As for self-control. You should really visit some community that was brought up without much education and parenting and where average IQ is around 90 (i.e. that of a slightly above average gorilla — btw. average human has IQ around 100). Then you will perhaps understand that self-control is not a measure of anything. Lest you deny those folks personhood as per your definition. Even a dog, properly educated, can exhibit enormous amounts of self-control (and dog's motivation to do so plays no role -- what's important is the actual ability). Cue in behavioral psychology. But more importantly, and as I repeat ad nauseam, personhood is first person perspective, i.e. consciousness, which is basically the leitmotif of transpersonal psychology.
Furthermore, neurobiology demonstrated that the cognitive functions you deem insignificant in animals and which by your standards define humanity and personhood (such as pattern processing, etc.) are common equally to humans as they exists in e.g. birds or lower mammals (as does the consciousness btw., but science has no definitive answers in this regard even though the fact is perfectly extrapolatable once one knows the nature of one's own consciousness). Sure, human is to date the only known animal with abstract pattern processing, but that feature obviously does not define our personhood (if it did, we would be persons in one moment and not-persons in another, lol.).
And finally, this all is perfectly knowable simply by detached observation of mental processes. And voila, the circle closes -- detachment is just a means to an end, not the goal itself. That it leads to peace of mind (nirvana), is just a side product. And let me assure you, peace of mind has nothing to do with void.
