Yeah, it's not great. I figure not being able to display specific things is something people who really need to can work around, but not even being able to find things means surrendering information to the void.
Just because one can't open the information by default doesn't mean the information doesn't exist - in this case, Flash content is exactly like your paywall and book examples. The searcher can decide if having access to the information is worth the added cost...regardless of it's buying the book, paying for the subscription to bypass the paywall, finding an old computer or setting up a VM to use flash.