Why are ravens so wussy?

Ok, so I’ve pretty much always known that a flock of crows is known as a murder of crows, as odd as it sounds the first time, it makes a certain amount of sense. Crows being scavengers and considered to be carrion birds, a gathering of them might well be a murder, or at least because of a murder.

Now I know that crows and ravens are not the same thing (Apart from when you’re talking about crow in the general sense of any member of the genus corvus) but I really don’t think I could probably tell the difference, although ravens are supposed to be larger, so I guess if I saw a really big crow I might call it a raven.
But anyways, like I said – they’re different, if not by much. So I guess it shouldn’t surprise me that a different term is used when referring to a flock of ravens.
What I do have trouble dealing with, is the name that they do get – an unkindness.
An UNKINDNESS?? What sort of wussy, half-hearted, non-committal name is that?
They’re Ravens. You don’t get a bird more sinister, evil – signifying or just plain creepy than a raven.
It wasn’t a crow tap, tapping on the chamber door was it?
And whilst people don’t always hate and fear the raven, they’re pretty much all in awe of it, whether it be as bringer of omens, source of wisdom, messenger of gods, or favourite form for many gods benevolent, malevolent or merely impudent.
So why does a flock of ravens, get such a wussy name?
Do ravens gather, watching on with grim purpose in their evil little eyes that send shivers up your spine, whenever someone insults your mother, or short changes you?
Or do a flock of ravens perched in a tree, croacking and cawing at you as you pass, nervously trying to avoid their attention mean that before this day is done, somehow whom thou holdest most dear, shalt stubbest their toe most bloodily?!

I can’t help thinking that someone was having a joke, and it just kind of stuck.

But then that seems to be par for the course when it comes to naming congregations of birds – if this page is anything to go by.
Who comes up with some of these? How many are really traditional collective nouns, and how many did someone just make up because that particular bird didn’t have one yet, and they thought it should?
I can’t help thinking that a flamboyance of flamingos falls into the later category.