Marginal costs outweigh the benefits so why would people buy? This is simple economics and they know this, but they still price fix because they must meet their minimum profits whatever that may be.
Its a common problem with monopolies, as soon as the market place shrinks to only a few players, where the means of production has been concentrated, those people then start dictating prices and may collude without even needing some conspiratorial agreement.
Many people also ignore the fact that Intel ME/AMT and the AMD equivalent features that cannot be disabled, are not documented, and are primary targets; are becoming more well known, and in general people don't want it.
Businesses may find value in those features, but individuals find cost (i.e. their privacy, and greater future risks that are unquantifiable).
They've broken their own market, and the rot will only get worse for them since its unlikely they will right the course. Many IT people wonder if there isn't some secret government mandate requiring these companies to embed management co-processors. It is clearly offering only minimal value to IT, and its seen as a cost for individuals that know about it.
They really need to reconsider their actual market instead of the fairy magic kingdom type thinking they have been following.