It's an interesting notion that you can't disagree or find faults in your friends, especially if we adapt the Anglophone definition of a friend as a loose sorta sustained contact. Would people rush to criticizing in this manner if someone truthfully wrote that their friend has problems hauling 20 kg weights up four floors of stairs?

The description is undiplomatic, could be written in a more roundabout way, but this could be read as even more haughty and rude. I'd say that as human collectives we need to maintain a grip on reality, and it is wasteful and dangerous to live in a web of polite lies.