IMO, an arrow straightener should be standard equipment for everyone who shoots aluminum. Yes, aluminum bends, but that means it can also be bent back and straightened. Even creases can be taken out, but I'll keep that procedure my little secret for now.
Most bends can be easily fixed with a little patience and experience with the tool. Even without the tool, a lot of bends can be straightened by hand. With a fine eye, or checking by spinning, they can be brought back at least as straight as a cheap carbon.
And, as bigbulls pointed out, the thicker the walls on aluminum arrows the more durable they are. I think .015" thickness is about the minimum for best durability. If you want light arrows for max speed, then you're better off with carbon than thin walled aluminum.
It's the light arrow speed freaks who came up with this idea that aluminum arrows are so fragile. Most of them never shot anything heavier than a 2213 or 2413 and have no idea what kind of punishment an arrow like a 2216 or 2315 can take before being damaged. Go on up the scale to 2219, 2317 or 2419 and they are extraordinarily tough. Plenty heavy and slower too, but they sure hit hard when they get there.
Disregarding aluminum arrows because they can bend is like saying bows with aluminum risers are crap because they can get bent.
Keeping with the theme, how bent aluminums can usually be straightened, it must be pointed out that a carbon that's not straight can not be straightened and will NEVER be straight.