Okay, does anyone actually believe that causes a problem?
I can think of ONE time when that causes a problem, and that's with indentation with multi-line strings. Oh look, HJSON included that feature. That's like throwing the baby out and keeping all the bathwater.
I can't find a specific example off the top of my head but I'll say I've been managing a Jekyll site for a while now and whitespace errors in frontmatter and data files cause all kinds of problems. I'm not sure I could explain the details but it's a legit criticism of YAML. IMO part of the problem is that YAML looks very straightfowrard and is until it suddenly isn't. Whitespace is part of that problem.
As an anecdote on the flip side, I've been building Middleman sites for a while now and can't remember ever having an issue with whitespace in the front matter or local data.
I can think of ONE time when that causes a problem, and that's with indentation with multi-line strings. Oh look, HJSON included that feature. That's like throwing the baby out and keeping all the bathwater.