Good discussion, and just a few quick thoughts as I'm running out the door.
The oly lifts are pretty technical. However, we can conclude a couple different things based on the observation of the shitty technique of most athletes: First, that the lifts are too complex to teach well in the limited amount of time most athletes have to learn them; or two, those instructing them are not doing a good job.
I think it's a combination of both. No football player is ever going to be as good at weightlifting as a weightlifter - duh. But I do think it's entirely possible to teach non-lifters sound enough technique in little enough time to reap some benefits that are not available through other means. However, I also will be the first to admit that you have to evaluate the circumstances and make smart choices - if it's clear this basic level of proficiency cannot be achieved for whatever reason, trying is not a good investment of time and energy.
Do the lifts mimic the movements in football? Not really. But neither does flipping a tire or throwing a keg. One could argue that flipping a tire is a lot more similar than a clean to a lineman's duties, and I would agree.
But the point is, "functional" or "productive" doesn't mean mimicry - it means developing physical qualities that improve the athlete's ability to play.
Yes, you can lift stuff quickly - whether a bar in a deadlift or a sandbag or, god-forbid, a kettlebell. But I would argue that no "speed lift" can match the top-end knee/hip extension speed of a snatch or clean. This is just a result of circumstance - you have an implement that can be kept in immediate proximity to the body and there is zero need to slow the implement down at the end of the movement (like a DL - you have to stop). That hip/leg power can then be used to improve upon movements like sandbag lifts, etc, and maybe even sprinting, cutting, pushing another gigantor dude around.
Having said all that, the o-lifts are only one small part of all the goodness to be used to prep footballers for the game, and teaching/learning them can't be allowed to unnecessarily limit the time put into actual training. I do think SM implements/exercises have a great deal of value for these folks (and most others). I just think the idea of using them, or anything else, as actual substitutes for oly lifts isn't legit.
Just my 2 cents, adjusted for inflation.