There is some important piece of context there though - if leaders aren't capable of the emotional intelligence to process blunt feedback, they are bad leaders and there is no hope of change. Learning to recognise them and just leave them alone is one of those valuable life skills that most employees learn sooner or later. Some people are just not going to take feedback and if they end up in management that is that; there is nothing to do but enjoy the show as best you can.
In that situation fluffing the feedback will do nothing. It might take years of effort to get marginal improvements and it is more productive to focus on something that is ... well ... more productive.
There is a lot of truth in this, but especially when developers are semi-randomly promoted into leadership roles, they should be given enough time (and mentorship) to learn from their own mistakes. Some will learn very quickly (those with enough emotional intelligence), and some will learn nothing no matter how much time you give them. Being a good manager with formidable leadership skills is something you can only get through experience.
> there is no hope of change.
There is an off chance that management (I'm not using the word leadership here deliberately) is taking leadership coaching, that the coaching is good, and that the coach will actually intervene and bring about change. Small likelihood of course, but not zero.