It’s not that people don’t know about it
it’s not that people are surprised by it
The point is that we all think it’s bad and that it should change and so we’re pointing it out
It used to be the case that everyone bought a bundle that included a bunch of free (not charged at point of use) services. Whether or not you took 3 bags, you paid the same price as someone who did. Whether or not you chose seats all together at time of ticketing, you paid the same as someone who did. With the advent of unbundling (in part driven by online search), consumers could now decide whether taking 3 bags was worth whatever $X the airline proposed to charge. For people who did choose that, they paid more than people who didn't use that service.
https://link.springer.com/article/10.1057/s41272-022-00388-5 has some more information about the evolution of unbundling.
For me personally, I prefer the unbundled approach; it fits my sense of connecting my costs to my consumption (and probably saves me money in total).
No, you think it's bad. I may despise Spirit and Frontier and refuse to fly them, but I also think it's a great thing they exist.
I despise them because the lack of comfort/nickle-and-diming is not worth my time, and I can easily afford to pay more for a better experience. But if I were back being 20 years old and broke, and my body could deal much better with being uncomfortable for a couple hours, I'd love the option to be able to fly on the cheap.
Edit: One big issue when flying for me the risk of cancellation and not being reimbursed, but I balance that against the ticket cost. Again, I often have some flexibility around staying in a location longer when necessary, which helps inform the carrier I select.