I'm confused. You begin your post with a stance that's typical of copyleft proponents, then you end it in the opposite direction.
There is a trait in human nature that pushes us to share our knowledge. But we would like this sharing to be mutual.
When I publish a piece of software for free, I would like others to read it, comment it, give me suggestions on how to make it better, and the whole community can benefit from the process.
Unfortunately, someone might instead take it, start making profit out of it, and never giving anything back to me or the community.
As a device to get the former effect and avoid the latter, a sort of "contract" was created that mimicks a copyright licence. It is called copyleft and says that you can do whatever you want with my work except profit.
Now, someone might say that stopping a third party from profiting out of something they have not made is correct, someone might say it nevertheless means removing a freedom from them.
Whose side are you on?
we all would like people to share their code with us, but forcing them to because of your license is extremely anti-freedom to me.
address this culturally, that is the only way to address this completely. legal means cannot fundamentally redirect the culture of a society and make them believe that sharing is better for everyone. if you want a society that shares what it creates, then help create THAT. forcing people to do it pushes them in the opposite direction, they want to grasp their things even tighter than before.
“we all would like corporations to share their products with us, but forcing us to pay because of their proprietary license is extremely anti-freedom to me”
No one is forcing you to do anything, and least of all which software licenses to depend on. If you don’t like something, choose something else. Freedom, you know?
Absolutely. That's how coding used to work in the 70s. Then software passed from people to companies, which proved alien to the cultural values that had hold so far. At the end of the 80s Stallman designed something to address the corporate world with a language they would understand. They had copyright, he created copyleft.
Now, please reread your post replacing "people" with "corporations" and check if it still sounds reasonable.