Nope Region. The word 'most' can be used with countable or uncountable nouns. Only the countable ones are used in the plural form.
Consider these examples of uncountable nouns, all use the singular form (i.e. the verb 'is').
Most of my hate mail is not in the same league
Most of my work is boring.
Most love is tragic.
Most of the water on Earth is salty.
Contrast that with these examples of countable nouns which use the plural....
Most pieces of hate mail are not in the same league [ notice the subject noun changed from 'mail' to 'pieces'].
Most of my projects are boring.
Most women are tragic.
Most of the bodies of water on Earth are salty.