EDIT: gnu.org also says "We do not recommend this license" ,pointing to the Apache license as providing better protection against 'patent treachery'. (https://www.gnu.org/licenses/license-list.html)
* It's not explicit that the user can redistribute the software freely.
* It's not explicit that you're free from warranty, meaning that, unlike basically all code ever written, you're on the hook for bugs and defects, just like a physical product.
Yes, it does say "do what you want," but that's not necessarily good enough for lawyers.
And if so, then have the capital letters mattered? Would it be less legally operative if written in camel case?
(2)Subject to subsection (3), to exclude or modify the implied warranty of merchantability or any part of it the language must mention merchantability and in case of a writing must be conspicuous, and to exclude or modify any implied warranty of fitness the exclusion must be by a writing and conspicuous. Language to exclude all implied warranties of fitness is sufficient if it states, for example, that "There are no warranties which extend beyond the description on the face hereof."
I don't know if the definition of "conspicuous" has ever been tested in court, but that's the idea. I'd be interested to see it used as ammunition against clickwrap EULAs, though.