I don't think that is a fair comment. Yes with a fly rod and a floating line you could pass the fly over the school of fish without snagging, but 90% of the fly fisherman I saw had heavy sink tips and long leaders. Best case the fish comes in snagged in the mouth, but just as many come in with the hook in the back. Drift guys with a short float actually have the same option of keeping the presentation above the fish, it always comes done to intent or lack of understanding. You can snag with anything. What disappoints me is when the ratio is heavily weighted to more snagged then fair hooked and "anglers" don't bother to make any changes to their setup. That should result in a ticket and forfeiture of gear.
I was there yesterday with the fly rod and, normally, I would agree that flies are the ticket with pinks. During the previous week, I couldn't keep the pinks off my flies. Yesterday was a different story. No matter what tip I used, I foul hooked way too many fish. Just picking up the line to cast would result in foul hooking fish. Not fun at all. Yes, I did manage to catch fish hooked in the mouth, and we all got our limit of chrome bright pinks. But the visibility was so poor, with lots of debris floating downriver.
My buddy (Stratocaster) also brought a drift rod with him, and after fly fishing he tried the drift rod with a fly under a float. He did pretty good - hooking many fish in the mouth; however, we suspect these fish may have been flossed. And yes, even short floating with the drift rod resulted in foul hooked fish! With visibility as poor as it was, I find it difficult to believe fish were biting but I guess you never really know. I would present my flies in the same drift, only to feel fish on the line (not biting). I was careful not to set the hook unless I felt the fish "mouthing" the fly (like a trout bite). Lost way too many flies breaking off on fish.
The water came right up, and it was a bit sketchy getting out. Be careful if you go out there!