I think the point here is that many people don't realise indexes matter so much in MongoDB. Their documentation doesn't go out the way to push indexes as a must. That coupled with the ease at which you can just start using it compared to say, MySQL, means that people find it interesting.
I will point out that while I wrote this, it was more to try and ensure other people don't make the same mistakes.
I will point out that while I wrote this, it was more to try and ensure other people don't make the same mistakes.