Because if nothing else, search optimization makes my life a whole lot easier than it was even 5 years ago.
It's the little things, like being able to put in the name of a local ice cream parlor and getting a map and all 6 locations as the first result. Or searching for a very specific technical question and finding the answer I was looking for more or less immediately. All that happens because more and more companies are optimizing their sites for search.
Point here being that while search is a great tool for marketers, the true benefit is to the consumer.