I generally dislike the word as well, _however_ it sorta makes sense in this context since it makes sense to think about the composition of our brains (and bodies). We are, of course, meat.
For the brain I think I prefer 'wet jelly' than 'meat bag'!
I always liked the term wetware
That may be true, but if you see yourself as a butcher, naturally, you tend to see everyone else as meat. The OP's disregard for "dumb people" is pretty obvious.
I am a dumb person. Ask me about colours sometime.