I disagree that consumer or customer behaviour is difficult to understand, I'm very much in the Rory Sutherland school there. But it is difficult to build into a business plan.
For example Brunchgate: saved a third of catering costs on J long haul. Great looking spreadsheet. But what is the effect on customer experience? How do we quantify it? It's obviously a big negative because a keep part of the perceived customer experience VP of J is "the finest wines known to mankind and restaurant quality food". We frequent fliers know that's not true, but a plate looking a little fancy gets you some way towards the expectation. On the other hand, if it's just a light breakfast there is obviously a HUGE disconnect. And then you look at differential costs and realise how much those "fine" wines and "great" food are costing you compared with what you can get on the ground, and you have blown a huge and probably irreparable hole in the brand perception and perceived value prop. With premium travel you are ultimately selling swish via ego and once the perception the product is something special goes it's difficult to rebuild.
Similarly no-one really argues with spend based status, it's the way of the world really. But the way the BAEC changes was sneaked out before New Year with patronising platitudes and really dreadful comms - not to mention a feeling that customers were being fired if they didn't meet the BA profile - has really damaged brand perception in a huge and valuable segment. A good brand perception enables higher margins, so losing sentiment hits the bottom line. It's a numbers game at the end of the day, so you lose a % of brand perception and that scales directly onto the outcome.
This people stuff isn't rocket science, it's very simple psychology. But you get people so wound around their ideas that you can't get this through to them. It's much easier to point to a number in the forecast outcome than it is to make the arguments about behaviours stick.
I really miss a lot of this since retirement, not that having a good handle on it was enough to counteract the accountancy led part of the deal in many (most) situations, I don't miss the parts of the meetings where good ideas are rejected because someone in R&D refuses to look until the business impact has been fully quantified. But I did enjoy understanding systems and behaviours.