To be fair this is an article that takes the opinions of employees of Rackspace, specifically, to deliver it's "verdict" which isn't a verdict so much as a collection of pluses and minuses. More importantly, Rackspace offers a Mongodb service (which they plug at the end of the article) so take their opinion with a grain of salt.

Kind of like a Chevrolet dealer writing an article offering a "verdict" on the Chevy Volt that consists of opinions of Chevy engineers and mechanics and ending the article with a link to their showroom selection. Not invalid but not objective and not really a verdict.