Aye yai yai. Ya know, your response is part of the problem here. This may be a general shift in the way this site is going, and that may be fine, but what I expect from the comments in HN posts is far greater than what SFjulie1 posted. It's incoherent, off-topic, and filled with the anti-{%database%} mentality prevalent when something about MongoDB comes up.
The comment raised an interesting way of thinking about the
problem that many developers would not consider
Fantastic! Why can we not have an actual discussion about scaling MongoDB when the post is about scaling MongoDB! You want to have a conversation about different database engine solutions to the problem, go start a post about that. But this post was about MongoDB scaling. I may have been critical of the GP here, but you fail to appreciate the need and desire to keep HN to the level it should be.