Good find, but a man can change his mind. Also, given the existing patent system, you're practically forced to seek patents to avoid getting trolled.
[Edit: I just picked a computationally relevant number that approximates the patent counter circa the epoch.]
How so? What if you released something in the public domain and made it unpatentable?
Of course, Knuth is notorious for his "churning out" of books; though none are as rigorous as his early VB6 stuff.