Frankly that seems more like a google search algorithm failure. I think the idea that people shouldn't produce content because you don't want to see it listed is more than a little silly.

Both situations can happen.

I think that ideally you write about a topic you've grappled with and know it well at that moment. I've done this a number of times and am really happy that people comment it's been useful.

On the other hand I've also come across many low quality articles as well.