Attribution licenses are not new ...
... as someone who has written commercial code *and* documentation for more years than I'm prepared to admit, I've had to put in attribution text/logos many many times. It's very standard with "pay for" software, DLLs etc.
For example, writing EDI software and wanting to use the SAP interface, means having to put in the appropriate logo and text somewhere in the documentation ...
... and surely people have spotted the number of Microsoft products that, when they start up, have small print in the splash screen saying something like "portions of this software are based on code from some small company that we bought and then crushed" or something like that?
For example, start up MS-Word, click on "Help >> About Microsoft Word", look at the long list of attributions for spelling dictionaries, templates etc.
It's more important to have this when you're not distributing source because otherwise the final user has no way of knowing who contributed to their application ... and we are all such fame hounds we need to let people know that *we* wrote that bit of code and not Microsoft :-)
Even when attribution is in the source I think you'll find most "users" out there won't read the source code. So having a popup or otherwise with your details in it is the only way of getting your company known as the best company for, say, progress bar dialogs.