Whence?

When you see such an image, you must be thinking of some specific word, in your mind.

What is that word?  Have it fixed in your mind. Now, tell me, how is that word pronounced?

For me, the word is M.O.U.N.T.A.I.N.  But for a distressingly growing number of the local populace, it seems to be pronounced something more like "mou-un".  I've been trying to imagine where the traditional middle part of the word got lost.

How does this mysterious evolution of language take place?  Who started it?

I fully recognize that the actual spelling of the word, M.O.U.N.T.A.I.N., has never in my recollection been strictly related to how we actually pronounce it.  But I was always of the impression that the mangling we do is fairly unanimous, and we have some consensus, about how to say this and most other words.

It appears that my impression was mistaken.  Not only do words change meaning, right before our eyes, but they also sound different.  I feel somehow let down by all of this.  Like an article of faith that I cling to has been callously violated, with some impunity.