quick synthesis should not fail why does it?

[Shadygrove]

What do you mean?

It always had a chance to fail if you were close to or under the item's level.

[TechnoTechie]

I've noticed control stats seem affect HQ rates during quick synths too; as soon as I upgraded my gear from 55(i100) to 60(i150) and melded a bunch of control to it I went from getting about 1% HQ rate to about an average of 10% (one time I even had 30 HQ out of 99 QS).

On the OP's regard for why it fails; it's so that people can't lazy-level by QSing things that are above their level for more exp. I've heard of people doing this to try and level and I think that's SE's way of saying "nope, get better gear/more lvls first scrub"

I've also had 0 fails since level 55 while quick synthing, and I've generally been keeping my gear up to date; I've quicksynthed roughly 2k+ items in the past month w/out failure, but I've also mostly been QSing things that are at least 2 levels below mine.