We Have to Talk
There's a pervasive communication problem that I feel it important to address.
Needs are things like oxygen, hydration, food, sleep, shelter — things that a person or other living must have in order to live, or things that a machine depends on in order to do its function.
Doing a chore, running an errand, filling out a form, signing a document, turning in an assignment, making a payment, and other things of that nature, are obligations, not needs. There's a difference.
Telling someone that they need to do something is to tell them harm will come to them if they don't. If it's a mere obligation, then saying they "need to" is unnecessarily rude, harsh, forceful, angry, condescending, threatening, and, unless they've really really wronged you, uncalled for. Saying it to someone at work is unreasonable. Saying it to a child is unconscionable.
Saying "I need you to..." is not much better because now you're accusing the person of harming you.
It really breaks my heart that our language has come to this. I'm trying to be reasonable here, but every time I hear someone make this grievous error, especially if they're smiling, it makes me distrust them so much more and respect them so much less.
References:
Slate.com - How Need to Vanquished Have to, Must, and Should (archived)
Word Hero - Kindergarten Imperative (archived)