Those are a lot of posts to quote and respond to. I think this topic has been stretched out quite a bit already so I'm not going to quote everyone.
I think Envenom was great when it was released in TBC (if I'm not mistaken, I didn't play in TBC so forgive me if I make any mistakes). What it did in TBC was consume all your Deadly Poison stacks, and then deal instant poison damage compared to what your Deadly Poison dot would have done if it ticked it's full duration, and then increases your chance to apply Deadly Poison again. So as an Assassination Rogue you were constantly building up your Deadly Poison, instantly doing all the poison damage and then get a boost to build them back up again. Over the years this concept got changed, altered, improved and now it's simply a weird concept that doesn't make much sense. It's just an Eviscerate that deals nature damage and gives you a higher chance to apply more nature damage. It's weird, and the whole concept and idea behind the ability is now lost.
I'm not sure what you mean with the Warrior examples though, I'd say all Warrior abilities make perfect sense and fit their theme really well. Even Dragon Roar makes perfect sense, Warriors or mainly Fury Warriors have always had abilities related to shouting. Dragon Roar is merely a large deafening shout. But anyway off topic.
Everything aside, I will continue to whine and complain about not getting a poison smoke bomb for as long as I play this game.