I’m tossing in another, “actually, you’re wrong.”
I’m here because the default is not intuitive. If it were, I wouldn’t have searched for this thread.
Suppose I have an amplifier with a backlit power button, the button in its “off” state would be greyed. Turn the amp on, and the power button becomes illuminated. To me, the first of this pair (grey is shown) would lead me to assume something is disabled.
If you have something with two states, you might want to show its current state. That’s why a Webex window with a big blue “chat” bubble is illuminated when the chat window is open and the “video” button is blue when your camera is on.
So, if you see a blue (illuminated) button stating “Enable”, using the intuition of the two prior paragraphs, you might think that is the moment that when you press “Next”, the third-party repos will be enabled. Making that button grey clearly indicates you do not want it enabled anymore, which is evidenced by the word “Disable” being part of the current state. It would probably be slightly clearer (and contrary to the current behavior) if those words were “Enabled” and “Disabled” instead, with a trailing d.
I’m certain you can find many examples/opinions on StackOverflow, HN, Reddit, and personal blogs of developers, where people debate the best layout for buttons in general. You can also find hundreds of upvotes on a discussion about this exact Fedora button.
Very simple tweaks (converting it to a check box; not dynamically changing the text) would improve its comprehensibility. It’s fine that Fedora wants to enforce UI uniformity, and confusing new users in the first few minutes of a Linux installation is the side effect.
With all that in mind, I would call a collective opinion a judgment. “Each to their own opinion,” sure… Maybe some people liked the Game of Thrones finale. Here, the available evidence shows that this button is confusing enough to prompt users to post/comment about it.
(It’s possible this has changed in F40. I just installed F38 as that’s the certification for the machine I’m using.)