Everyone likes choice, right?
I agree, this offering isn't bad because it is additional choice onto not too bad plans in the first place. I don't think that's the argument here - the problem is about giving more power to ISPs, whom I don't trust with that power.
It enables ISPs to be massive, colossal dicks if they can get away with it. (As in, if they lose a few customers but gain a lot of revenue, they totally will stifle people's internet.) While it is currently about adding options, what's to stop them from slowing your internet down solely to get you to pay more for 'packages' to 'unlock the full experience'? They can just put up speed bumps and charge you for removing them. That might not be a problem in a competitive, big market but that's not how the internet market is these days in most countries. Why won't this result in a race to the bottom in oligopolies?