There’s no reason for someone to avoid dairy altogether unless there is an intolerance allergy etc. on a personal level as a T2 with weight problems I find if I eat too much dairy especially butter and cheese I gain weight so I do limit them slightly, I eat them but it’s not where I get my main source of fats, I use extra virgin olive oil, avocado oil and avocados, fatty cuts of meat, Greek yogurt and a few nuts, as long as your eating enough fat to feel full for long enough then there’s no reason to eat loads of dairy if you don’t want to