I am unsure why Intuit wants me to share my tax data with Intuit. Is the form saying that I won't get all the savings if I don't share?

Once you sign the disclosure, Intuit uses your information to provide personalized offers for your unique financial situation. 

You can unsubscribe to stop receiving these offers by going to the latest Turbo email and clicking the unsubscribe link. 

See TurboTax FAQ: https://ttlc.intuit.com/replies/6307719