I think the point of the OP is that RNG inherently implies "randomness" which is a misnomer.
To those of you who say "RNG is RNG," I would call you
more correct than those saying "RNG is random" which is just wrong. This has been proven and posted publically:
Diablo 3 Legendary Drop Rates Revealed | Diablo: IncGamers
We can have a very convoluted discussion about theoretical drop rates and hypothetical analogies, but let's just make a simple example:
If there is a 1/100 chance that a drop is a legendary (my bot picks up about 100 items for every legendary so I'll start there)
And there is a 1/500 shot at it being a particular item (Remember smart loot isn't a guarantee so class specific set items are only drops not to consider).
(1/100*1/500) = 1/50,000 or 0.0005% chance that an exact legendary will drop.
The basic chances that you would get that exact items two times in a row would be (1/50000*1/50000) = 1 in 2.5 million or 0.0000000004
Again it's hypothetically junk, but you get the idea. The chances of getting a particular item like a Wand of Woh for example, is very scarce. Some people play hundreds of hours and never see one. Yet there are people who have two drop in one game. My buddy has found 4 thunderfuries from enemies, gambled 3, gotten 2 from objects. All were well rolled. Who else has that luck?
TL : DR:
It's not "random" it's the suggestion of random with forced weighting to make certain items extremely scarce.
It would appear to have certain loot on certain servers or items that frequently drop on certain accounts. It creates a temporary pool of legendaries that you CAN find.
My personal feeling is that this per-account or server loot table rotates or it's server based.
My drops have definitely been limited to about 20 different items, then all of a sudden there is a new 20 items that I am getting multiples of.
//blasphemy