You're absolutely right, but you can't just throw your hands up and say the GMs and owners have no say in where a player plays as you kind of implied.
What I meant was that nobody forced Toronto, per se, to give Marner a full NMC that prevented his going to Carolina. Maybe you pay him an extra [insert dollar figure here] a year and make it a 24 team NTC.
Point is, that is part of the job of being a GM--deciding who is worth that kind of contract. The best GMs create flexibility by having the clause kick in in X year or end in Y year or change to a lower level of trade protection in Z year. All I'm trying to say is that you can't blame a player who earned their contract for not waiving the trade protection that their GM afforded them and act like the GM had no agency in the matter.