Whether at a sum that decision was lucrative or not is inconsequential, as that comes down to how the market responds to their decision, but what you can argue is whether they make more off headsets now than before.
Before they bundled regular corded buds, and you purchased new ones when your old ones broke. Now they sell $180 USD AirPods, and Beats, and bundle (IMO) clunky adapters. While I don't have data on this, I'm fairly confident in assuming their decision was made on this basis. The question is if this turned out as they hoped in sales.
> The simpler explanation in my mind is that Apple wanted a thinner phone, and they did what they needed.
How so, when there was obviously space enough for an end-user to fit a jack inside the final product?
Looking at the iFixIt teardowns[0], where is this space supposedly at? If you remove electronics, sure, maybe you could fit it, but there very definitely is components where he put the headphone jack.
They still do. The iPhone 7 comes with Lightning headphones AND a Lightning-to-analog-jack adaptor.
They also sell the bundled headphones separately, so you can replace them.
Not really, there was a little bit of space near the old jack, and he removed a critical part of the barometer to make the rest of the space. If you're removing parts you can't exactly claim that it was empty space.
Well, such a condition would rely on this being true and accurate. I'm not really confident there's any data that suggests how people are listening to music on their iPhone 7s at the moment, and really nothing to draw a conclusion from except "anecdata". The simpler explanation in my mind is that Apple wanted a thinner phone, and they did what they needed.
There was an article a few days ago from Xiaomi's Indian Product Manager who commented on the removal of the Headphone Jack on one of the Mi Phone releases. His insight was that despite what people say ("I don't care about thickness"), their surveys and testing overwhelmingly showed that consumers have a preference towards thinner phones.
With this in mind, to me it seems more reasonable that Apple just decided to ditch the jack less they be caught making the fat phone. Your personal preferences may differ, but I think the more reasonable and sustainable conclusion is simply that Apple is chasing the thin phone.