Let's talk about the 'tyranny of happiness'

[Tonus]

The problem is that it is being stated as an absolute: "if you do A, you always get B."  In other words, the premise is making a promise it can't keep.

That is one part of the problem. The other part is that it implies that if you don't get B, you're doing something wrong in life or something is wrong with you. It puts the person at fault for their own misery, which is not always the case, and it demonizes negative feelings, which are necessary in a healthy emotional life.

As I said, this isn't to say that looking for positives in life or striving to be happier or to make one's life better is wrong. Just that this type of thinking is sure to do the opposite.

Part of the problem, IMO, is that humans are not very good at accurately determining the extent to which we're at fault for anything. So depending on our mindset, we might give ourselves too much or too little blame or credit when things do or don't work out. It also means that you can't apply a specific solution to everyone's situation because some people will be motivated to act if you convince them that they're the reason their lives are so bad, but others will be crushed by such a claim and sink into despair.

I guess in that sense, the notion of a positive outlook as a defacto problem-solver is a way of trying to find the simplest solution to complicated problems. They're the fad diets of attitude adjustment.