Most positioning fails for a reason nobody wants to write down, which is that the business was never willing to lose anything.
Everything else is downstream of that. The vagueness, the committee language, the statements that could belong to any of eleven competitors: those are symptoms. The disease is an unwillingness to be unavailable to somebody.
Positioning is a trade. You become the obvious answer for a narrower group of people, and in exchange you become the wrong answer for everyone else. That second half is the entire mechanism. Take it out and you have not made positioning safer, you have made it inert. A position that excludes nobody informs nobody.
But exclusion is difficult to sign off, because the people signing it off can name the revenue they are giving up and cannot name the revenue they will gain. The loss is specific and immediate. The gain is diffuse and eighteen months out. Of course the loss wins. It wins in almost every company, almost every time, and the result is a position that has been negotiated down until it is a description of the sector with a logo attached.
The second reason is that positioning is usually run as a marketing project when it is a business decision. If it lives with the CMO, its scope is communications, and its output will be communications. It will not touch pricing, portfolio, hiring, or which clients you fire. It cannot, because those are not the CMO's to touch. So the strategy is real but the levers are not connected, and a year later everyone concludes that positioning does not work. Positioning worked. It just was not allowed near anything.
The third reason is research used as cover. There is a version of this work where the company commissions enough customer research to make the decision feel inevitable rather than chosen, and then discovers, as everyone does, that customers describe what they already know. Research tells you the shape of the room. It cannot tell you where to stand, because where to stand is a bet about the future and customers do not have one. Somebody has to decide. That is uncomfortable and it is meant to be.
The fourth is timing, and this one is more sympathetic. Positions are often set at a moment of low confidence, after a bad year, during a merger, in the first quarter of a new CEO. Low confidence produces defensive positions. Defensive positions describe competence. Competence is the least differentiating claim available, because it is the price of entry and everyone claims it anyway.
There is a fifth reason that I only started to see clearly after running an agency rather than advising one. Positioning fails when nobody inside the business is personally exposed by it. If the position is wrong, whose year is bad. If no name attaches, no conviction attaches either, and a position without conviction lasts until the first client who pushes back on scope.
What the good ones have in common is not better writing. It is that somebody stood behind a choice that could have gone the other way, said no to work that would have paid, and held the line long enough for the market to notice.
That is unglamorous and it is most of the job.