NLP differs from positive thinking. Although many NLP practitioners prefer good feelings over feeling bad; and many NLP techniques (but not all) imply that feeling good works better, NLP also works with negative stuff.  In the end if something works one can make a NLP strategy out of it and if that strategy involves negativity then there is nothing within NLP that forbids it. Even if most NLP practitioners might not like it. Also there are many NLP strategies that are neutral when it comes to feelings. There is a NLP strategy for boiling an egg, but it has really little to do with feeling good or bad.

Hedonism, pessimism, utilitarianism, eudamonianism: these are all ways of thinking that measure the value of things according to pleasure and pain, which is to say according to incidental states and trivialities. They are all foreground ways of thinking and naivetes, and nobody who is conscious of both formative powers and an artist’s conscience will fail to regard them with scorn as well as pity. Pity for you! That is certainly not pity as you understand it: it is not pity for social “distress,” for “society” with its sick and injured, for people depraved and destroyed from the beginning as they lie around us on the ground; even less is it pity for the grumbling, dejected, rebellious slave strata who strive for dominance – they call it “freedom.” Our pity is a higher, more far-sighted pity: – we see how humanity is becoming smaller, how you are making it smaller! – and there are moments when we look on your pity with indescribable alarm, when we fight this pity –, when we find your seriousness more dangerous than any sort of thoughtlessness. You want, if possible (and no “if possible” is crazier) to abolish suffering. And us? – it looks as though we would prefer it to be heightened and made even worse than it has ever been! Well-being as you understand it – that is no goal; it looks to us like an end ! – a condition that immediately renders people ridiculous and despicable – that makes their decline into something desirable! The discipline of suffering, of great suffering – don’t you know that this discipline has been the sole cause of every enhancement in humanity so far? The tension that breeds strength into the unhappy soul, its shudder at the sight of great destruction, its inventiveness and courage in enduring, surviving, interpreting, and exploiting unhappiness, and whatever depth, secrecy, whatever masks, spirit, cunning, greatness it has been given: – weren’t these the gifts of suffering, of the disciple of great suffering? In human beings, creature and creator are combined: in humans there is material, fragments, abundance, clay, dirt, nonsense, chaos; but in humans there is also creator, maker, hammer-hardness, spectator-divinity and seventh day: – do you understand this contrast? And that your pity is aimed at the “creature in humans,” at what needs to be molded, broken, forged, torn, burnt, seared and purified, – at what necessarily needs to suffer and should suffer? And our pity – don’t you realize who our inverted pity is aimed at when it fights against your pity as the worst of all pampering and weaknesses? – Pity against pity, then! – But to say it again: there are problems that are higher than any problems of pleasure, pain, or pity; and any philosophy that stops with these is a piece of naivete.

Beyond Good & Evil paragraph 225