Runes of Magic US / AU

So ever since I started playing this game back in chapter III everyone's been telling me not to loot the chests in FA and NoM because they decrease the value of boss drops. To this day, new players tell me they've been told the same thing. What surprises me though is that I've never seen any evidence to support this claim.

So where does this rumor come from?
Is it just a myth, or is there any conclusive evidence to suggest a correlation between the rare drops of bosses, and the chests in these, and other dungeons?

Quoted from "ruisen2000;588530"

Opened a chest once, and still got 2 purples from 2 FA bosses...

As interesting as that is to hear, it only concludes that it's possible to get purple drops when you loot the chests, which I actually already had done myself. It doesn't say much about the drop rates as 1 run is hardly a very good test, and flukes happen every once in a while, and often they're more likely to be reported than the most likely outcomes.

I've been doing some testing myself, but It takes a lot of runs to notice a difference, if there is any. Both with and without looting the chests I have gotten purple drops, and sometimes no drops. From what I've noticed, there's not much in the favor of this myth. If there is a difference, it's a very small one.

It'd still also like to hear if anyone has ideas on how this myth got started.

My best guess is people avoided them because the loot is so poor aside from some blend runes, and opening them takes time away from grinding the instance. Somewhere in the grapevine "chests have poor loot" turned into "Chests make loot poor". Plus people get superstitious and like to come up with reasons why they're not getting the drops they want.

Note that I'm still not calling this myth busted just yet. I'm still open to more information on the topic. If anyone has conclusive evidence for or against the myth, I'm all ears.