@Dirtclustit, I believe that you are making the popular argument that "veto rights" aren't inherently bad because decent people will use them responsibly and not just because they get a bit jealous or scared. I think this is true, for the most part, but I still believe even more strongly that people use them as a crutch, a false sense of security that they do still have control over their partner's other relationships.
When it comes to a veto, if you are a decent person and have a healthy relationship, all your partners will be able to approach you with an issue anyway. You won't continue something that is causing your partner undue pain. This does not mean that you will stop doing anything they don't like, but it does mean that you will try and reassure them that the thing you are doing is not meant to make them feel less valuable and make steps to reassure them of their place in your life in other ways. Sometimes you reach an impasse and that thing is something that you need and your partner can't tolerate and so, hopefully amicably, you decide to end the relationship as it isn't healthy to continue it. If this is how decent people in healthy relationships act, why would you need an official rule that states "you will treat me decently"? Your partner should feel they can approach you with an issue, they shouldn't need the protection of a "rule" that allows them to have their opinion.