Merkuri
Explorer
When I first came across a power worded like this, I was confused for probably all of 30 seconds. I realized almost immediately that Close powers don't provoke, and I thought, "Oh, that's a neat way to make a ranged attack that doesn't provoke!"
Regarding making everything clear within the power and not having to reference other rules and keywords, that would make some really wordy powers. Would you imagine having to write out the meaning of status effects, like Dazed, each time a power references one? Sure, in a perfect world you'd like to be able to make each power understandable on its own, but that's just not a good use of space.
Also, for powers that work similarly you'll end up having a ton of text that's identical between the two, and you'll have to painstakingly scan through the two powers to find out what's different between them. Finding the little bit of text in the large paragraph that says "Does not provoke" may take you longer than looking up what a Close Burst attack is and what makes it different from a Ranged attack. (Plus, once you look that up once, odds are you will remember it for next time and not need to look it up again.)
The fact of the matter is, although we're not computers, our brains are incredibly powerful. We have good memories and logic centers, and we're able to remember that a Close power has an area of effect, an origin square in your space, and doesn't provoke. And if you don't remember it, you probably know how to look it up in the PHB or the Compendium.
Also, the more you use this information the more likely you are to remember it, so players with a small amount of powers are pretty likely to remember how they work after they've used those powers in a few battles. Without looking anything up, I know as an Invoker in my Monday night game that Sun Strike is a Ranged 10 attack and I will get hit if I try to use it when an ogre with a club is standing next to me. I also know that Astral Wind is a better choice in that situation, because not only will it push the ogre away from me, but the ogre doesn't get to hit me for using it.
But if I go for a few months without playing that Invoker and my knowledge of Sun Strike and Astral Wind gets rusty, I can read "Ranged 10" and "Close Blast 3" and know immediately which of those powers is good to use when there's a goblin standing next to me.
Regarding making everything clear within the power and not having to reference other rules and keywords, that would make some really wordy powers. Would you imagine having to write out the meaning of status effects, like Dazed, each time a power references one? Sure, in a perfect world you'd like to be able to make each power understandable on its own, but that's just not a good use of space.
Also, for powers that work similarly you'll end up having a ton of text that's identical between the two, and you'll have to painstakingly scan through the two powers to find out what's different between them. Finding the little bit of text in the large paragraph that says "Does not provoke" may take you longer than looking up what a Close Burst attack is and what makes it different from a Ranged attack. (Plus, once you look that up once, odds are you will remember it for next time and not need to look it up again.)
The fact of the matter is, although we're not computers, our brains are incredibly powerful. We have good memories and logic centers, and we're able to remember that a Close power has an area of effect, an origin square in your space, and doesn't provoke. And if you don't remember it, you probably know how to look it up in the PHB or the Compendium.
Also, the more you use this information the more likely you are to remember it, so players with a small amount of powers are pretty likely to remember how they work after they've used those powers in a few battles. Without looking anything up, I know as an Invoker in my Monday night game that Sun Strike is a Ranged 10 attack and I will get hit if I try to use it when an ogre with a club is standing next to me. I also know that Astral Wind is a better choice in that situation, because not only will it push the ogre away from me, but the ogre doesn't get to hit me for using it.
But if I go for a few months without playing that Invoker and my knowledge of Sun Strike and Astral Wind gets rusty, I can read "Ranged 10" and "Close Blast 3" and know immediately which of those powers is good to use when there's a goblin standing next to me.