Their incentive is to make money by providing goods or services to customers, which is the same as every business. Go buy something from the department store, give them your phone number when they ask for it, and tell me you don't receive spam calls afterward.

Given all that Google knows about you, i'd say they're actually quite polite in how invasive they are. I'd much rather them have this data than 99% of the other companies out there.

It sounds like you basically just hate businesses that collect data. I'm sorry to break it to you, but there are a ton of them.