Now then...I am really pleased to see that there are folk on here willing to stick there necks out
I am a firm believer, and always have been, that a rod with a more through action allows fish to be played quicker and more efficiently than a stiff rod.
The reason is the curve of the rod protects the leader against sudden lunges and head thrashes. This means you can use lighter leaders but apply more pressure than a stiffer rod, as has already been pointed out, fluro lines do not take kindly to "shock"..ie, a sudden pull.
Suprised no one has mentioned teeth. I have lost a few trout and on inspecting the leader its been frayed...or I ave unhooked a trout and the leader has been "roughed up" by the teeth.