All of Mashiro's argument is just headcanon. I think the best retort for people who, even if in good intention, always tries to pry in your personal matters is to let them handle it and never butt in. Everything that happens to a relationship should only be solved by the party involved within said relationship. Never ever third wheel, even in their problems. It's okay to give advice in a calm way but don't do what Mashiro did and doompost every second of her life like it is the end of the world or whatever and there is only like two choices like she suggested when in reality there is a lot of ways in handling a problem since surprise surprise the world isn't just black and white. I get her concern, I really do but what she did was more harm than good.
That said, Tsubakida is surprisingly understanding of the situation. For a supposed "Delinquent" of their school, he managed to stay quiet, listen and gave his own opinion of the situation he is currently in without throwing a single tantrum. Made him much likeable tbh.