

They lose no customers by including it. They lose some by omitting it.
So it boils down to being too expensive to include? Hardly!
You evaluate prior decisions with posterior data. But you fail to take into account the counterfactuals. How do you know how much the FP4 would have sold with a jack?
Claiming that an increase in sales validates the goodness of the decision is not causal.
It is the same logic that would tell you that playing russian roulette is worthwile in case you win and get some reward. That’s backwards rationalization, fitting a narrative.
If market research universally showed that people don’t care about a jack then why do some phones still have it? Are these manufacturers going against the grain? Surely they wouldn’t leave money on the table if it worked like that.
The justification of “they do what sells units” is backwards. It would imply that no product would ever flop. But products regularly do. There is no telling in advance how it will perform, and saying otherwise is falling prey to the problem of induction, whether past observarions justify predictions.
The FP4 could have broke sales records for a multitude of reasons. How can you say which factor caused it when there is only one scenario that played out? We don’t have alternative universes to compare, where they released one with a jack, or another with some other altered specs.
Money is a powerful motivator to do really crappy things, and Apple has done exactly that for decades now. Others are following suit in the lucrative accessory market.
But this is the smoking gun, pointed at the consumer.
Dongles are an admission that the phones they come with don’t work in the way the company knows its consumers need them to.
Almost as insidious as how the inkjet printer manufacturers vendor lock and upcharge for ink. Profitable? Indeed. Despicable and anti-consumer? Very much so.