Demanding precision in spoken language is possibly one of the most off-putting and unsociable things one can do. I cringe every time I hear someone correct someone else for any reason other than complete misunderstanding. If one understands the message being conveyed, why does it matter how the message is conveyed? This sort of attitude is the antithesis of good communication.
On the other hand, most written forms of language should be held to a fairly high standard; if only because presumably the author had both the time and interest available to proofread the work they write.
Requiring this of spoken language is tantamount to requiring that all shirts you see be tucked in and all shoes shined. It's not going to happen, and it makes the requirer seem petty and pedantic at best, stricken with a mental illness at worst.