Because Arachnos weapons are limited to VEATs only and the only way to do that was to make them exclusive of any other weapons for those ATs. At the current time there appears to be no other way to do it without inadvertently making the Arachnos weapons available to all.
I too would like more customization with my VEATs, but it seems there are some hurdles the devs need to jump before they will be able to allow it.
Widows are limited to using Widow blades? It's completely shocking! 
http://www.fimfiction.net/story/36641/My-Little-Exalt
[ QUOTE ]
So I get to where I want to changeup my Widow's claws and -POW- (queue the wimpy, groaning trombone slide)... You can't change the widow blades.
Can someone at the very least provide a valid reason for this?
[/ QUOTE ]
It's because they are trained to use those blades, if you're looking for an RP reason.
A game mechanic reason why? Because the Devs said so.
Also, you may want to look up what 'epic' means in terms of the Epic ATs. It means that they are tied in with the story of the game, and yes, the widows only use that one type of blade, so widow characters are forced to use them.
Let me never fall into the vulgar mistake of dreaming that I am persecuted whenever I am contradicted.
~Ralph Waldo Emerson
"I was just the one with the most unsolicited sombrero." - Traegus
"Because Arachnos weapons are limited to VEATs only"...
But the "Widow Blades" ARE available to other ATs.
Scrappers and Stalkers both can utilize the widow's claw graphics at any point.
[ QUOTE ]
"Because Arachnos weapons are limited to VEATs only"...
But the "Widow Blades" ARE available to other ATs.
Scrappers and Stalkers both can utilize the widow's claw graphics at any point.
[/ QUOTE ]
Yes, but only one of their styles is available to them.
There is only one style. Widows don't have options. Just the one, and it's the same one available to everyone.
[ QUOTE ]
But the "Widow Blades" ARE available to other ATs.
[/ QUOTE ]
Yes and I think BAB, Posi or one of the Devs said that was a mistake and if they could go back they would make Widow Blades only availavle to widows.
"All right, they're on our left, they're on our right, they're in front of us, they're behind us...they can't get away this time"- Chesty Puller US Marine Corps
The mechanical reason that Widows don't get to customize is twofold:
1> The projectile is part of a power, and we don't have power customization.
2> The giant claw that pops out of the hand is part of the power, and we don't have power customization yet.
Until we have power customization, these two parts will always match the default widow claw, and look dumb if we're given a different looking claw.
And it was BAB that said giving the claws to scrappers/stalkers was a dumb move.
@Roderick
[ QUOTE ]
There is only one style. Widows don't have options. Just the one, and it's the same one available to everyone.
[/ QUOTE ]
That's odd, because it appears my Widow has access to two different styles of Widow Claws. Both have a tintable and a non-tintable version. Do I have a benefit that no one else does?
You apparently have an option that I lack. 
I'd really like to have other models available, but at least the ability to tint would be nice.
Either way, thanks everyone for the feedback. It would appear my original assumption was correct, and Widows simply cannot customize their weapons. Bummer.
So this past weekend I finally got my first villain to 50, and was very stoked about trying out the VEATs. Me and a friend both rolled one of each and proceeded to kick the tires and generally just roam around getting the missions done through 10 so we could at least unlock the 1st "normal" costume slot.
I should say we had a blast and the ATs are a lot of fun. I think I am favoring the Widow, but then something happened that more or less ruined my experience.
I really have a lot of fun with the character/costume creation in this game. It's a big reason I continue to play and reap a lot of enjoyment through a very light hearted RP play style.
So I get to where I want to changeup my Widow's claws and -POW- (queue the wimpy, groaning trombone slide)... You can't change the widow blades.
Can someone at the very least provide a valid reason for this?
And what about this: every stalker and scrapper in the game can use the "epic archetype" widow blade graphic, but the "epic AT" is limited to only one choice??? How is that "epic"? How is that even fair?
I realize this is nit-picky, but it seems like such a simple little thing. I shouldn't let it spoil my fun with the AT, but just the same, I was REALLY bummed I couldn't utilize one of the other claw graphics. Really, really dissapointed. Anyone have comments? Suggestions? Similar experience?
Perhaps this has been discussed significantly in the past, and I apologize if this is old news, but I am (obviously) new to the VEATs. Cheers!