I don't think what I said was bullshit. So you wrote tests to make mongo fail, and you've seen cases where people run into problems with it. That still doesn't disprove my point. With postgres, you roll your own sharding. With mongo, you don't have to.
It seems you fall squarely into the bucket of 'people who haven't even tried' (and some other unfavorable buckets, but I'll leave that to your older self to judge).