The GPL is an implicit contract. Anybody who happens along and acquires a copy of the GPL'd code is supposedly bound by this 'contract.'Wrong. Notice that it is typically contained in a file called 'COPYING'. The GPL only applies when you redistribute the software.
It's a heck of a lot like an EULA in that regard, and nobody here takes binding EULA's seriously. Why should we take the GPL seriously either?It's not like a EULA at all. A distribution license like the GPL is not invoked until you distribute the software to someone else. A EULA is a contract that is invoked when you install a piece of software (or sometimes, when you open the box).
The GPL guarantees you to have no restrictions on your use of the software. Above and beyond that, it grants you certain distribution rights that you would not have otherwise under copyright law. If you reject the terms of the GPL, you may not distribute the software, but you can still use it for whatever purpose you want. A EULA, on the other hand, is designed to disallow you to even make use of the software if you do not accept its terms.
See the difference now?