They've had other customers in the past and present, and could have others in the future. Should they take less money to not take the money from Google?
This idealism is nice but if you remove privacy unfriendly customers you rule out basically every customer and don't have the money to make a browser at all. Behind Google are Bing, Yahoo, Yandex, and Baidu before you reach duckduckgo who somewhat respects privacy.
