So people like to freak out write in caps, make fools of them selves and just being pests.
Anyhow there is truth to the rage.

You should always rake damage over AS/Crit when playing a range carry. The simplest reason is that in order to deal damage with AS/Crit you need time to stay still which is not often the smartest thing to do. With damage you can better poke, preposition, poke, rinse and repeat which is what you need to do as carry. Standing still and just auto attack is a luxury and more an exception than the general rule.

As for build I find the following to be the best choice:
- Doran's Blade
- BF Sword
- Boots (Zerker best choice Swift or Merc are good choices too)
- Infinity Edge
- Zeal -> Phantom
- Banshee
- Stuff ...

Always include some survivability in your build.

Well sure with all the best times we can possibly image and that if we could get those items every game then sure why not?

I'm not talking hypotetical. I try to present the best plausible consistent build that is also used by several of the best players out there. If you look at the Season 1 championship you will notice that most ashes are built the way I describe or close to it. That is why I adhere to that build.

When doing a build, at least a consistent one, you need to take all stages of the game into consideration and maximizes your potential (or close to it) every step of the way. It's all fine to conjure 6 best items you'd like on a champion, anyone can do that, but the trick is how do you get to that point in the first place.

So sure you could come up with a build that is stronger. But can you farm it every time? How consistent is it? How well does it perform in a lvl 9ish team fight etc?

EDIT: To answer your question more directly: Sure it is survivability, but should you get focused it typically will not be enough. The point as Ashe is avoiding focus while dealing damage, easier said that done, but once you know how to do that you don't need the life steal. Banshee is mostly a safety for that one time you get out of position and eat a stun or some nasty AE effect and gives you the chance to get the heck out of there. The build is describe is focused on playing carry in a team that knows how to do team fights, not random solo hammering all over the map.

I don't really play my Ashe anymore since she takes so long to develop and truly epitomizes the idea of carry.

However, 2 IE and 2 Warmogs makes no sense.

2 IE is bad because IE is so expensive - the first investment is justified by the unique passive which won't apply to the second.

Warmogs - Ashe is primarily a glass cannon, and extra health won't save you much from your primary opponents/targets. If you really need to fit a survival item, Banshee's is very helpful providing that shield and some needed hp and mana along with mag res. Defensive items don't go far on Ashe as she'll generally get bust down regardless, so your priority should be dealing as much damage as possible when you can.

IE, 2 Phantoms (the movement is especially helpful, the attack speed and crit chance practically required) Some type of armor pen (Black cleaver is very useful unless the team is really really tanky and armor stacked - then you're stuck with Last Whisper).

Boots would primarily be beserkers or swiftness depending on preference, tho merc treads if the team is cc heavy.

You need lifesteal, so I'd suggest either Bloodthirster if you're focusing dmg over speed, or starks for its overall usefulness - For me hitting over 2 attacks per second takes priority

which leaves one spot for defensive if you dont go complete glass cannon - tho some people do prefer 2 defensive items.

Omg don't tell me that is in order.
Why in the world would anyone ever rush a phantom dancer?
That is just ridiculous.
It's like rushing a FoN on Mordekaiser.

But anyways my order depends on game and how well I'm doing:
AD+Support Bot

Doran's blade
->Doran's blade (if not good farm/harass)
Boots
->Brutalizer (not enough to get BF Sword, they have little to no heals, spam Volley, low armor enemies)
BF Sword
-> Finish Berzerker's Greaves (or after Infinity Edge if farmed well)
Infinity Edge
Zeal
->Last Whisper (if start stack armor, if not, get after Phantom Dancer)
Phantom Dancer
Banshee's Veil/Bloodthirster