And you can argue that EUA isn't fair, but it is not illegal, and has nothing to do with software theft, except as a lousy excuse.
How about credut cards? Property of the bank! Venue tickets? Usually no way to return or resell legally, especially once you've entered the venue. Music? I don't like this song, it's faulty.. I'll just return it.
Software developers realise that it might be bad for their business if users can't try the software first, so they will usually provide a trial version. But if they for whatever reason do not wish to - it's up to them.
And there have been many instances where developers realised that the software really does not do its purpose and gave compensations to their customers (Win95 version of RAM Doubler, to name one).
The very nature of software makes it difficult to
1) determine that it isn't faulty
2) user does not continue to use it once the original copy has been returned