You don't even know what coke is, since that formula is kept secret (well, Coca Cola's at least). Also, in some countries, you'll get high-fructose corn syrup instead of cane sugar, which is believed to increase the risk of fatty liver disease, obesity etc. (caveat: Some believe the evidence is not conclusive enough for certainty.)

And why don't they just "sell you coke" everywhere? Because it makes them more money. And the raison d'etre of a commercial company/corporation is pecuniary gain. Profiting. Making money. Management is obligated to act so as to maximize profit (under legal obligations etc. etc.)

This brings us to your first point:

> it's a pretty paranoid take on the market economy.

No, it's literally what commercial companies' charters and fundamental structure requires. No conspiracy theory or paranoia.

In context of spying - if the company has determined their profits would improve by them spying on you, and that they can get away with it - then it's pretty likely they will indeed spy on you.