Why is studying abroad always criticized as just getting a "water master's degree"? How to fight back?

The reason is, I was chatting with classmates, and then a male classmate said: "Is the air abroad better than in China, and there's 💰, but now the overall situation is not good, studying abroad is not feasible." This really got on my nerves. I still haven't calmed down. What do you think I should do? In a class group with forty people, making a scene is embarrassing. If I stay silent, I keep getting angrier. Fortunately, my sisterhood stepped in and said: "None of your business!!" After that, they started criticizing, asking if I'm only nice to those with money, and things escalated into a real mess. In the future, how can I effectively retaliate against such people without making it seem like I care? I wish everyone smooth sailing in their studies abroad.