Agreed.
I wouldn't mind, as an archer, a limit of (for example) 7 seconds of hold. Longer than this, and the archer actually looses his arrow, and gets stuned (like a kick animation), cause his fingers couldn't handle it. Let's even add a 1dmg to self when that happens.
Anyway, i rarely see archer holding their aim for more than 7 seconds. Except the afkers, leeching, feinting to shoot.