From Destinypedia, the Destiny wiki
In short, misinterpreted line from Rahool. I've put it in the "unknown" category.
Hey, no problem. Basically the rule is that other than the first word, only proper nouns get capitalized. Most pages are proper nouns so there is a lot of capitalization. Nothing is even really official yet, but if for example subtitles say "Use a Ghost shell to blah blah" then we know shell isn't a proper noun.