Why are they still spending hundreds of millions on ads with athletes and other things that provoke a healthy image?
Because we're all monkey-brained. There are uncountable examples of this.
Because they are foolish enough to believe that advertising actually works to influence people's behavior. Or because they are afraid that their bosses are similarly foolish, so they will get punished if they try to do Coca-Cola the favor of cutting that extreme waste from the budget.
These pixels are a horse of a different color. They grab my info with no consent given (hiding behind "But the site we have the pixel on has to inform you, not us!" is a complete and utter cop out) and then make a profit selling or using it.
Totally different circumstances, and this shouldn't be ok.