I grew up using spinners for trout. In fact I was making spinners before I started tying flies at around age 10. Along with tying bucktail jigs, dressing hooks for spinners was more or less how I got into tying flies. There was a local type of spinner which everyone called a "Short Striker" which had a fly pattern of any sort, trailed by a small (#14 or so) treble hook, and had a weighted bead body and a french-style blade. Similar to but better than a Joe's Fly. I continue to make these to this day, they are deadly on trout and also panfish. No, there is no NEED for the small treble stinger, but I can't count how many fish I've caught which were hooked only by it. Rainbows especially are notorious for trailing and nipping at the tail... hence the name "Short Striker".
I have 100% as much satisfaction catching fish on lures I've made myself as I do on flies I've tied myself... In fact in the case of these spinners, I've tied the fly AND made the rest of the lure, so there are even more processes and skill which go into it. I love to fly fish, and there were plenty of times when I would rather fly fish than anything- lately though I've learned that I have as much fun fishing PERIOD... fly fishing isn't always the most fun or the right answer.
Spinners work great for trout. End of story.
To the simpleton, proof does not matter once emotion takes hold of an issue.