I agree with this and also was thinking hmmm 'what if that were me that someone was wondering how to 'end' the friendship with?'
I'd far rather someone was just a bit distant and non communicative and repeatedly said 'sorry, I don't have time' to any suggested meet ups, than made some big issue. The message would pretty quickly deliver!
Also, in terms of 'friendship' or rather 'acquaintance', I attend a lot of adult education classes and there's a couple of people I'm in repeat regular company with that the way they speak and the things they say literally repulse me (mainly snobbery, one-upmanship, disrespectful, condescention, high conflict, provocative, disharmonious, people).
What I've taken from this is a) don't engage with what they're saying or doing (as my particular mind wants to leap and grab onto their 'wrongdoing' -and it is wrong- and 'do something') but there's nothing can be done as they enjoy conflict.
As the sayings go: "don't wrestle with pigs, you both get dirty and they enjoy it" plus "don't argue with an idiot, they'll drag you down to their level and beat you with experience".
The main thing when in the company of someone being openly rude and provocative is not to play the game. Ever. Don't let them 'hook' you. But do laugh and dismiss their rudeness and defend anyone they're bullying. Then they won't want to hang out with you.
Example: in a coffee shop, Horrid Friend says 'good god look at the state of that fat waitress, she's putting me off my food'. You say in a lighthearted tone 'ooooh, what's she ever done wrong to you! that's the nastiest thing I've heard anyone say in years, do you really feel so hateful towards her? I think she's really beautiful and she's got absolutely gorgeous hair'. H Friend: 'ugh she's revolting'; You (laughing) : 'well don't look at her then!', 'and just so you know, I don't agree so it's subjective I suppose'. When conversations repeatedly unfold like this H Friend no longer wants to hang out with you.
Example: H Friend says 'did you get dressed in the dark today or something?'. You laugh 'ha! no, I just have a lot of errands to run today and don't care what I'm wearing'. H Friend 'well I prefer someone's dressed well if I'm having lunch here'. You: 'You know what, I've got a busy day today and I don't want to eat with you now if you're being weird and bitchy, let's forget it hey?'
It is very important to stand in your own power and never allow the disparaging person to put you on the other foot or make you less than or worse, feel reactive - that's what they want. Don't play the game.