The definition of milk literally includes plant milks. Milk has been used to describe these beverages for as long as they have existed.

I have seen coconut milk sold as 'coconut drink', even though it is not used as drink. That is stupid.

But calling it "almond milk" is waaay smoother than "almond drink" or "almond concoction"

By having to give it a weird name those products and the sustainability argument behind it get associated with weirdness, and are less appealing to people who might otherwise consider trying them.

"Creamy nut juice" just didn't do very well in the test marketing

The problem i have is just that i walk into a store, buy some cheese for my cheese toast, then later at home discover it's not "cheese" but some disgusting mixture of plant oils and flavour agents that makes me want to vomit and throw up.

The problem is not vegan products existing, but them deceiving and tricking the ordinary person about what they are with no clear labeling. It simply has to be explicit that it is not what a normal person thinks when they read "cheese", but some other experimental food instead.