Google (well, I shouldn't pick on google. All brokers of advertising) optimize to push you towards the product that their customers are willing to pay the highest ad rates for.
Of course, In a company concerned with it's long-term reputation, googlers will point out, this is modulated by a knowledge that they need annoy the customer less than any alternative.
My point is that an ad is always going to cause the broker to have a conflict between what the user needs and what the customer is willing to pay for, while an organic search result (unless it competes with an ad, which it often does) does not cause that conflict for the ad broker.
Huh? Advertisers want to make as much money as possible. Consumers want to pay as little as possible for the best goods.
This is a fundamental conflict for a company that has no way to add value for the consumer.
First? google only displays ads from companies that pay them for ads. Next? they order those ads by how much money they can make from those ads.
Do you really think that how much a company is willing to pay to get a consumer to see an ad has anything to do with how good of a deal that product is? If anything, the relationship is going to be inverse. I'll pay you more for a high-margin customer than a low-margin customer.