the most efficient or most clear way to express a thought!

I agree, Bean. It's just that we are then operating within a particular speech community that has its own terms and consensus on meaning, which may well be marginally or completely at odds with non-specialist understanding of the 'same' word. I think that's what generates most of the heat in popular language discussion: it's a collision of two speech communities.

My fickle fingers keep wanting to type 'speach' - I shall have to wear the bottoms of my trousers rolled...