If eating meat or consumption of alcohol wrong in Sikhism? Then why do so many Sikhs do otherwise?

In Sikhism, taking any kind of drugs is wrong. But about the meat which is recorded in the Rehat Maryada, which is approved from the Akal Takht. It is written in it – Sikh ne kutha maas ni khana means prepared in Muslim way. Also known as halal meat.