> you must agree to X, before you use the product you bought
To my understanding in many countries this is already illegal in practical terms. Users in those countries are usually permitted to just click through those kinds of agreements and they'll hold no legal water. A EULA must be shown before the user obtains the application or appliance (this for example is why Steam will ask you through click through accepting any third party EULAs before you can download a game and why third party EULAs for a game are listed and readable in an attention drawing yellow bar on their store page) and "back of the box link to the EULA" isn't allowed. (And even then, the majority of stuff in EULAs that goes beyond the liability-related stuff is illegal anyway since they forbid things that are considered rights you just have.)
The US is basically the only country where these kinds of shrinkwrap EULAs tend to have more use than fancy toilet paper as far as I know.
It's not illegal, it's just not legally binding. Accepting an EULA after purchase is more like "we would like you to comply to these license terms, but if you violate them, we can't do anything"
In a lot of countries only the terms that were accepted during purchasing are legally binding. So if you buy a windows license in a shop without signing a contract, than no additional terms except general copyright laws apply.
With SaaS and online services this got way more complicated though. They can always ask to accept new conditions and stop providing their services if you don't accept them.
> Meaning you can't use the software because that would be copyright infringement?
Using the software is explicitly not copyright infringement. Private modification probably isn't either. Generally you don't need anyone's license to use your private property as you see fit; copyright is an exception but it only applies to a limited set of things.
Dishing out an EULA that contains non-enforceable terms should be criminalized. Probably if the deck wasn't so stacked for business, it would be quite clear to interpret such EULAs as fraud or attempted fraud.
But as the GP said, the whole thing is a total corrupt farce.
Technically EULAs with non-enforceable terms are meant to be thrown out as a whole in court, even in the US.
Unfortunately every lawyer quickly caught on that their explorative legal fiction being thrown out entirely might make their employer unhappy, so most EULAs have some sort of clause that if a part becomes unenforceable, it won't break up the entire thing.
To my understanding in many countries this is already illegal in practical terms. Users in those countries are usually permitted to just click through those kinds of agreements and they'll hold no legal water. A EULA must be shown before the user obtains the application or appliance (this for example is why Steam will ask you through click through accepting any third party EULAs before you can download a game and why third party EULAs for a game are listed and readable in an attention drawing yellow bar on their store page) and "back of the box link to the EULA" isn't allowed. (And even then, the majority of stuff in EULAs that goes beyond the liability-related stuff is illegal anyway since they forbid things that are considered rights you just have.)
The US is basically the only country where these kinds of shrinkwrap EULAs tend to have more use than fancy toilet paper as far as I know.
(I am however, not a lawyer.)