I've spent many a year working in support and also as a medical technician working with patients, and a year or so doing TA work. I've done a lot of hand-holding when getting a point across, and I've always done well in performance reviews. I'm quite aware of the human on the other end of the line. I'm here to tell you that it does take extra time. 'Manners cost nothing' is a not a statement referring to time.

There is also a difference between being rude and being frank. And there is a continuum of response between 'trying not to be an arsehole' and 'being an arsehole' - it's not a binary choice.

Why does being frank suddenly mean you've lost 'basic humanity'? That kind of opinion is a disease in itself.