Apple manufactures bluetooth headphones also [0] .. do the math. The really popular Beats headphones for example are made by Apple indirectly. By cutting off the headphone connection, they are encouraging people to buy new products instead of using old and proven technologies.
Apple has done this all the time during their history, eg. look at the whole adapter situation where you just have to buy extra hardware to connect your new device to anything.
And this is where whole "ecosystem" comes in.
If you switch, you will either have to replace all of your devices, or have inconveniences while using them together.
Apple has done this all the time during their history, eg. look at the whole adapter situation where you just have to buy extra hardware to connect your new device to anything.
[0] "Beats Electronics LLC is a subsidiary of Apple Inc." (https://en.wikipedia.org/wiki/Beats_Electronics)