Why do Indian parents say, 'Be grateful for everything we provide'?

Once, I asked my father for a ₹25K phone, but he bought a Vivo phone worth ₹15K without telling me. When I asked him about it and reminded him that I had requested a ₹25K phone, he angrily said, 'Be grateful for everything I provide. There are kids who don’t even have this ₹15K phone.' I agreed. Later, when I scored 90% in my 10th standard exams, he asked, 'Why only 90%?' I replied, 'Be grateful for my percentage. There are kids who failed their subjects.' Then he got angry, like WTF! Why does this 'grateful' logic not work both ways?