showing relevant searches is the key to stay in business for search engines, so if you search for "HOW TO DO SEO" but Search engines show "LEARN SEO" that's not quite relevant, is it.
True they earn from ADS but why Traffic trust them cz of relevancy only. Just for that reason they stopped Location based searches too cz they don't want to give you searches for "NEARBY FLOWER SHOP" from Manhattan if you are searching it from Canada. If you do SEO in the right way and for relevancy only and for long term purpose, you are there, if you do it with bad practice, you will be one of the guys who would say SEO is dead.