He's frequently on a powertrip and confidently wrong about so many things. For instance he's one of the people who perpetuate the "Javascript is fast and you don't need to optimize anything" falsehood. No wonder he's bringing in 100 polyfills into everyone's project. He thinks JS is C.
I am _appreciative_ that people like him exist, because -- personal feelings aside -- we do need people who have his level of dedication in the open source space.
My only interactions with ljharb have been in TC39. More often than not when looking at issues he's active in, I find myself wanting a level of maturity and thoughtfulness that just isn't there.
His contributions are neither novel or very compelling. He's more of an open-source bureaucrat than an engineer or a developer, yet he is currently steering several major TC39 proposals. I've seen him shutdown or sidetrack valid input and criticisms in all of them. The vibes I get from his behavior are akin to him being a member of "the cool kid club" -- wanting to maintain that ingroup/outgroup boundary very tightly.
He really should just get out of the standards/committee space entirely for the time being, and get some coaching on leadership skills before reentering. I realize this is super negative. Still on the ropes whether or not this feedback belongs in the public space.