Why do you suggest drinking green tea without milk?

The reason that milk is not drunk with Green teas is traditionally rather a hard-and-fast rule, as many people do add milk to green tea as a personal preference. There is nothing to stop you drinking it the way you want to.

Adding milk to black tea did not start until 1680 in Europe. The Chinese and Japanese never add milk to their green teas as they believe it changes its delicate flavour. Tea contains many nutrients; flavonoids, amino acids, vitamins (C, E and K), caffeine and polysaccharides and is thought that adding milk may change the absorption of these nutrients. Also thought to neutralize tannins and reduce acidity.

As we base the Green tea on the traditional method of drinking the hence the instructs to drink it without milk