"Can I get"

[Facilitatingdarkness]

What's wrong with "Can I have"?

It doesn't even make grammatical sense! I've noticed it more and more when people are ordering coffee, to the point that more people say it than not.

Makes me irrationally angry. Just me?

This used to rile my English teacher, who countered with (in a loud voice )
ONLY YOU KNOW IF YOU CAN, ONLY I KNOW IF YOU MAY.

I work in a shop , hear it all the time
Can I get a strawberry elf bar
Please can I get a bag?
Can I get 2 large costas, pump 6 and number 2 scratch card please?
Can I just get this please...... Oh and pump 5, 20 cigs, 4 lottos and a partridge in a pear tree

The worst thing is the overuse of the word 'grab.' The word grab has quite negative connotations because it implies rudeness and selfishness. Yet, how come it's dropped into every sentence these days? Can I grab your number? Can we grab coffee? Shall we grab lunch? No, I don't think so. You can ask for my number politely. If I go for a coffee, I will take my time and enjoy it. Same for lunch. Life is not a smash and grab raid, nor is it about 'getting'. How did this happen to the English language? Where have manners and consideration gone?