That is up to our governments to decide if such is allowed or not. For example, it isn't allowed to sell a gun or drugs with an apple (at least not here in The Netherlands, YMMV).

That you can decide to not go for the entire package is not what we disagree on (apart from above, I suppose).

What we were discussing is that the consent is optional; it is not in any of these examples. It is part of the package deal; then you don't call it opt-in or opt-out, as that allows you to opt-in or opt-out of something which is otherwise not in your direct advantage, but is in the other party's advantage.