I think it is a very good argument. I'm really taken aback by seemingly everyone playing dumb. Maybe I'm dumb. I feel like I'm in the twilight zone.

Displaying whatever you want on your website is an established thing. It might not be a very friendly thing (unskippable ads, etc.), but it's ok. The user visits you for what you have to say, and you say it. Going to the candy store with your car and hearing the owner tell you about his new candy, or even his opinion about your car, is fine.

But having your car tell you, unprompted, not to go to this candy store, but rather to the one owned by the car brand, is nuts. It's not okay. How on earth can people equate these two things?