Both EULAs and FOSS licenses are license agreements. Presenting them in the same way is not disingenuous. The length of the GNU GPL rivals that of some EULAs.
If you do not need to agree to a license before you use a piece of software, then EULAs would be invalid. You do need to agree to the license before you use the software. That the license grants permission to run the software for any purpose, usually with a disclaimer of liability, is irrelevant.
If you do not comply with (for instance), the terms of the GNU GPLv2, then you no longer have a license to the software. That means that you must cease distributing and using that piece of software or be at risk of a lawsuit from the copyright holder.
The standard dodge is that it refers to the "owner of a copy", while EULAs claim that you do not own a copy and are only "licensing" it. Which is BS in my opinion, but regardless the GPL specifically doesn't make that claim, so you don't need to accept anything to run GPL software.
As others in this thread have said already, the GPL is written such that it does not need to be accepted in order to use the software.
> If you do not need to agree to a license before you use a piece of software, then EULAs would be invalid.
I believe the GPL was written the way it was, in order to remove any concern that it might not be enforceable. If someday the courts decide EULAs aren't enforceable, the GPL would still stand.
Of course, the GPL also relies on standard copyright law forbidding modification and distribution without express permission, so if the courts ever change that then the GPL is in trouble since it's not an EULA. But that seems pretty unlikely.
If you do not need to agree to a license before you use a piece of software, then EULAs would be invalid. You do need to agree to the license before you use the software. That the license grants permission to run the software for any purpose, usually with a disclaimer of liability, is irrelevant.
If you do not comply with (for instance), the terms of the GNU GPLv2, then you no longer have a license to the software. That means that you must cease distributing and using that piece of software or be at risk of a lawsuit from the copyright holder.