I've read it, but I'm not a big fan of niceness in this context. There's a reason why all groups that try to get things done effectively seem to drift towards blunt and rude end of the spectrum. Niceness is an overhead, but it's also a highly asymmetric overhead - some points of view are taxed by niceness requirements far worse than others, so it ends up introducing a pretty drastic bias. For example status quo supporters tend to have least trouble being "nice".

Alicorn might be well-meaning here, but I haven't seen any decent evidence that niceness is appropriate in this context.