Fishing apparently uses quality of one's fishing implements to determine what is caught, in addition to depth, flow, bait, and time, and possibly local modifiers. While the others make sense, having quality change what you acquire does not. Why? Because unlike all the other factors, you can't change your skill level for survival- or rather, you can only change it to be better. In other words, you can be punished for getting better at fishing, because now you aren't getting what you want.
Consider plaice; it can be easily caught with low-level lures, lines, and rods, if you know where to find it. This is good. But as soon as you level up too far, break you 2-q line and get a better hook or something, bam, nothing but Pikespam, which might be nice, but certainly won't help you get that perception you where looking for.