the user isn't merely ignoring the output though, they are actively interacting with the program in a way that the program is presenting as accepting of the agreement being presented to the user.

the agreement is plainly presented in a way that implies that it's an obligation, like any other clickwrap agreement. and everyone except ole and stallman seems to agree that it's self-evidently apparent that it's a clickwrap agreement restricting the freedoms of the user.

"free software that only prints a message and exits unless you agree to a clickwrap with further licensing terms" is not a road that FSF should go down. And it's only because of the GPL severability clause that it's not a crisis, everyone knows it's a farce, except for a bunch of the users, who are affirmatively taking action to indicate consent with an additional licensing agreement.

it's not facially clear that in most jurisdictions that the clickwrap agreement is null and void merely because the software is free. you can end up paying for lots of free stuff in life if you're not careful. you agreed to the agreement, it's on you.

you are of course free to remove the prompt and use the software yourself, and ole rants and raves about that on his website. but, agreeing to the license is a separate thing from the GPL license, most likely. just like paying for credit monitoring is different from getting your free credit reports or freezes - they'll try and railroad you into paying, definitely! and just because it's supposed to be free, doesn't mean you're not getting charged if you agree to it!