With quite a few installer programs the licence is stored as a text file licence.txt, what is stopping me from modifying or replacing the license file with something else? I also recall either a program or registration on a web page where the licence was in a text box that was editable - so you could just select the whole license and delete it or change it as you saw fit.
To me it seems that you can't prove that someone accepted a EULA - or with a computer with multiple users, who accepted it. I think at least when you agree to an EULA, it needs to record your name and what you agreed to, and send it back to the company, ignoring the privacy issue for the moment, just so that the licenser has a copy of the agreement the licensee agreed to and who that licensee is.
IANAL, but I think that you need to agree to the license before you get the software, rather than after.
If all else fails, lower your standards.