The reason why Moutai is not called Moutai is because originally foreigners pronounced it like this when they read the word "Maotai". Considering that this pronunciation has become famous internationally, Moutai took this transliteration name.
MOUTAI is not the pinyin of Moutai, but the English name of Moutai. "MOUTAI" is the internationally registered trademark of Moutai, not the Chinese pinyin. In terms of English pronunciation, ou is pronounced as "au" (ahhh), and the mouth opens and closes naturally, while ao is pronounced as "o" (a sound between "oh" and "concave"). There is a tendency to be nervous, which is quite laborious to put it bluntly. In terms of English spelling, the frequency of ou is much higher than that of ao.
It is more common in English and looks more natural because they are all famous brand products that were well-known at home and abroad before the founding of the People's Republic of China. At that time, people also had to have names when communicating with foreigners. They were named by foreigners based on our transliteration. Such English names, and the pinyin we use now were invented and promoted after the founding of the People's Republic of China. There is no need for these well-known brands to change their English names, because this may lose foreign markets and the gain is not worth the loss.
The past of Moutai Factory
In the Qing Dynasty, the liquor industry in Moutai Town flourished, and famous liquors such as "Maotai Spring", "Maotai Shaochun" and "Tongsha Moutai" became famous. "Huamao" is the predecessor of Moutai. In the forty-third year of Kangxi's reign, "Gaisheng Shaofang" officially named its wine Moutai. Before 1949, the production of Maotai liquor was in decline, and there were only three distilleries, namely: "Chengyi Distillery" funded by the Hua surname, called "Huamao"; and "Ronghe Distillery" funded by the Wang surname, called "Huamao". "Wang Mao"; "Hengxing Winery" funded by the surname Lai is called "Lai Mao".
In 1951, the government merged three private breweries, Chengyi (Huamao), Ronghe (Wangmao), and Hengxing (Laimao), through redemption, confiscation, and takeover, and implemented three Maotai Heyi Policy—The state-owned Moutai Distillery was established.