Eh, you could have said the same thing when they removed serial ports, 3.5" floppy drives, CD drives, etc. etc. etc.
Yes, the world is moving forward. Yes, it's a little inconvenient.
And yes, this was apparently Steve Job's idea, as he felt that fans were "too noisy and inelegant". I imagine that he felt that fans were holding humanity back, and smugly told people who disagreed that they were clinging to obsolete technology.
It got so bad, that Apple actually advised their customers to physically lift and drop their Apple IIIs to re-seat the chips that had popped out from the excessive heat.[2]
Of course, if today Apple decided that fans were obsolete again, and the latest Macbooks were twice as heavy and still overheated, then it would become the new normal, and it would be hard to find computers that had fans anymore, and we would long for the days when we could just use computers for as long as we wanted without worrying about them overheating. And on the internet, commenters would say that it wasn't a big deal at all, and if you were some sort of power user that wanted to use your laptop for more than a few hours at a time, you should buy a $250 cooling pad for it.
[1]: http://lowendmac.com/2015/apple-iii-chaos-apples-first-failu...
It still has a fan though.
If? Apple's recent laptops have been notoriously undercooled, and the processors can only run near full speed for a brief moment.
The only difference is that they throttle instead of self-damaging.
The use-case for the 3.5mm headphone jack is still well and truly within the mainstream, and will probably stay there for some time as per the comment in the blog:
the right pair of headphones was the pair of headphones in front of you, or in your pocket, or mangled at the bottom of your bag. It didn’t matter.
There's a lot of legacy-weight hanging around in people's houses, bags, and workplaces.
Your point, however, isn't completely lost on me. I still miss CD drives occasionally, having to retrieve an older laptop in order to grab data from a disc I haven't yet bothered to archive to an ISO file. However, removing a CD drive from a laptop feels like a much higher percentage space saver than losing the 3.5mm jack from a smartphone.
The world didn't care about wireless headphones until their wired option was taken away. It's a solution to a problem of their own making.