As lovely as the explanation may be, it focuses on a single issue. The whole point of the GPL is granting and protecting end-user rights - protecting the developer from lawsuits is a secondary concern.
The end-user is not the developer who re-uses GPL'd code, but the guy who uses the final program.
By licensing code under the GPL, you grant the end-user the right to use and modify any program using your code as he sees fit (as long as he adheres to the rules of the GPL on re-distribution), and no intermediate developer can legally take that right away.
Of course this restricts the freedom of indermediate developers, but the GPL is intentionally -Ouser, not -Odeveloper. It just so happens that some users are also developers.
> What end-user rights does the GPL grant or protect that the BSD license doesn't?
The right to receive a copy of the implementation of the program they are using and re-distribute it freely.
I say "right" here, because in the case of BSD source on the internet it could be more accurately coined an "election" to distribute the source. As you say, "whatever the hell you want." Which is fine. So is requiring copies to carry a complete copy, including the human-readable form, and the rights to redistribute those, ala GPL.
