Joyent used to have the license on the top of virtually EVERY file in the repo for node. Someone removed all but one (6430 deletions) https://github.com/iojs/io.js/pull/311/files
I remember this was a common thing in free/open source projects some time ago[0].
At some point people started to believe that this was not necessary.
I am not sure of the legal implications, of either choice, just wanted to point out that the joyent people probably were not crazy :)
In every Berne Convention signatory country (which is pretty much any country that will matter to most people), published works are required by the convention to be copyrighted by default, whether or not there is a copyright notice, and the lack of a license means you have to assume you have none unless something else tells you differently. That basically makes embedding the license text pointless.
It certainly was common, though, which is/was probably because the US did not join until 1989, and prior to that US copyright law required a mandatory copyright notice, so a lot of people will have at least worked on projects old enough for this policy to have mattered.
Really? I've been putting the license in every file in my project because it's JavaScript and people drive by a website, see "foo.js" and have no idea where it came from or what license it's under. With the license in the file it's immediately clear.
Usually you'd concatenate and minify deployed JavaScript anyway. Sometimes you get a license in that, sometimes you don't. I don't think that many people really copy that much JavaScript from live sites these days...
> That basically makes embedding the license text pointless.
Embedding the license makes sense because otherwise others have to assume they don't have the right to use. The copyright notice on the other hand is pointless.
"The copyright and license notice is already in the LICENSE file. There is no justifiable reason to also require that it be included in every file, since the individual files are not individually distributed except as part of the entire package."
I can imagine this makes up for a portion of it.