The community is not for Linux vs Windows or to humor Linux users. It is for dumping on Linux and it's evangelists. I'm not going to let evangelists take over and trash it. This simple solution isn't blaming the user (common evangelist BS), it isn't making a false claim of Linux being 'better' for it. -So I see no harm in it and updooted it myself.
Actually if you open a file you only have read access to in Windows, it will be exactly the same.
Save it to your desktop, get rights, copy it to its original location.
One very minor detail to note, in your test you weren't actually overwriting the original file that you opened, but instead Notepad appended a .txt to the filename, which is its default behavior, but you still got the same type or error because you didn't have write permission for any file in that directory.
That very well may be a toxic trope in the Linux community, but in this specific case, I'd say it actually is the user's fault.
Since you believe it is the operating system's fault, I am curious how would you like the operating system to behave differently than this, when a user interacts with a file that they have read permissions but not write permissions? What should it do? The cool thing about Linux is that if you have a better idea, you are free to implement it and make it reality, and maybe even contribute it so that others can benefit too
Personally, I feel this behavior is already the best way to go, and why it works this way in all operating systems (at least that I am aware of). I understand that it makes it easy for the user to make this mistake, but I think it would be wrong to block the user from reading a file that they have permissions to read, obviously it would be wrong to allow them to write when they do not have permission, and at least (on Linux) they are given the option to save their changes to an alternative location that they have write permissions for, and warned when opening a readonly file for editing. Is there a better way?