If you don't know how it works, it's only because you haven't bothered to look it up.
Not exactly. You only know how PageRank worked at the very beginning, when it was patented. That is far from "the" Google search algorithm these days. It remains one of the most important ones, and possibly one that's fundamental to how Google's whole search engine works, but they have many, many other algorithms that govern search results today. Most of these are not patented, mainly for the reasons mentioned earlier: If Google patented them, it would have to disclose how they work. Instead, they maintain them as trade secrets, like the formula for Coca-Cola.
In Disney's case, I think it's not really interested in competing with Google. It would much rather Google, Bing, etc look at its patent, say "OK, I can do that if it will get Disney off my back" and implement the patent for little-to-no royalty fees.