From the author's conclusion after outlining concrete examples:
When you read the terms and conditions of Stack Exchange (which is I see as nothing more than
a vanity product for mathematically inclined people with delusions of grandeur), you realise what
an outrageous system it is. The Stack Exchange owns all your intellectual property!! That is
the ultimate vanity product dressed up as a sel
ess community-spirited venture. They can ride
o the coat tails of all your work and ultimately publish aggregated material for a fee and you
get nothing. You can put on your CV that you have such and such a reputation but it amounts
to nothing in dollar terms for you. I have better things to do with my time than support a
business model that is so o ensive to people trying to understand mathematics. But given that
stumbling on a good response (which do exist by the way) is a bit like a random walk, do you
feel lucky?
> You agree that any and all content, including without limitation any and all text, graphics, logos, tools, photographs, images, illustrations, software or source code, audio and video, animations, and product feedback (collectively, “Content”) that you provide to the public Network (collectively, “Subscriber Content”), is perpetually and irrevocably licensed to Stack Overflow on a worldwide, royalty-free, non-exclusive basis pursuant to Creative Commons licensing terms (CC BY-SA 4.0), and you grant Stack Overflow the perpetual and irrevocable right and license to access, use, process, copy, distribute, export, display and to commercially exploit such Subscriber Content,
So, Stack Exchange does not "all your intellectual property". You still control the copyright and free to use it elsewhere - that's the "non-exclusive basis" part.
You can also use someone else's contribution, under the same CC BY-SA 4.0 terms.
When you read the terms and conditions of Stack Exchange (which is I see as nothing more than a vanity product for mathematically inclined people with delusions of grandeur), you realise what an outrageous system it is. The Stack Exchange owns all your intellectual property!! That is the ultimate vanity product dressed up as a sel ess community-spirited venture. They can ride o the coat tails of all your work and ultimately publish aggregated material for a fee and you get nothing. You can put on your CV that you have such and such a reputation but it amounts to nothing in dollar terms for you. I have better things to do with my time than support a business model that is so o ensive to people trying to understand mathematics. But given that stumbling on a good response (which do exist by the way) is a bit like a random walk, do you feel lucky?