Really, i think this can not be allowed, at least not for the default browser. You also get a EULA when installing Opera, but it is not the standard browser you get upon initial install. The basic, clean-install Ubuntu expirience should be EULA free. There are some solutions perhaps to get past this;
- Add a global EULA during install, which would cover all (default) installed software, but that would be hard because almost no 2 EULAs are the same.
- Add the EULA to the default home page of firefox in Ubuntu , just expand it with the EULA or a notice about it.
The browser is for a lot of people the one-and-only application these days, it deserves to deliver the best expirience, and there are good alternatives available that do not impose restrictions on use.