It just does a pretty good job of dealing with binary files in general. The check in/check out model is perfect for unmergeable files; you can purge old revisions; all the metadata is server side, so you only pay for the files you get; partial gets are well supported. And so, if you're going to maintain a set of tools that everybody is going to use to build your project, the Perforce depot is the obvious place to put them. Your project's source code is already there!

(There are various good reasons why you might not! But "because binary files shouldn't go in version control" is not one of them)