Many people don't consider search quality at all and just use what's served to them.
I understand that someone reading HN would find that hard to believe, but when I look at some people around me who are not working in tech - many wouldn't be able to tell difference between Bing and Google search results. All they know is they can type/say a query and get the site they are looking for. The only time they would start thinking about underlying tech. is if they started to consistently get unusable results.
Google results are better, but how many people are actually aware of that (outside IT crowd) is questionable.