The biggest issue I have heard of with the stock springs is if the car has sat for a while, the spring can get rusty and gets pitting. When you get the car back to life, the spring will fatigue from the pitting. If the free length is fine and there's no rust, those springs will go and go.
Rusty springs go straight into the recycle bin, every single time
Heck, even suspension springs will break if they're being used close to coil bind and have rust. The safety factor on a spring is really low for most applications.