Why invent such a language?
I was inspired by the words spelled uhuh and uh-uh and mean 'yes' and 'no' respectively. So I thought how would a language made up of solely nasal sounds be? And ‘Mhmmz is my answer to that question.
Why would people speak such a language?
I imagine it spoken by a sect, that wants to rid themselves of all
opinion. They gave up speaking, because that way they avoid anyone
quoting them for having an opinion. Some of the extremists even sew
their mouths shut, leaving only enough room for a straw of bamboo,
through which they could eat mashed foods.
But they couldn't keep it up,
so eventually they started communicating in this language. Although if
you asked them, they would deny that it is language (I'm going to make
‘Mhmmz mean 'non-language'). (And, yes, denying that what they speak is language, is opinion: I didn't say
that they didn't have opinion, that's just their ideal, but most of them
can't live up to it)