I love these questions...because as I start writing my opinions I always start arguing with myself as to why I am wrong. This is a cat that can be skinned a number of ways and I think is answered more effectively by looking at the strengths of the coach involved than as a general principle applicable to all. You need to coach to your strengths and also look to the needs analysis and requirements of both your team and the individuals in that team.
Are you dealing with a bunch of high school lads that are all massive for their age or are they a little on the light side? Do they have the foundation strength that they need and need to improve their power and mobility? Or are they so light that a few seasons of strength work is still going to leave them barely moving the needle on the scale? Coach to your strengths and their needs.
The first point I'd always look to clarify is that of how confident and competent you are in teaching these lifts? How well can you get across the key teaching points? I mean you don't necessarily need to be an expert to teach but if you aren't confident in the key technical aspects you'll struggle to get the lads up to speed with these lifts. So lets assume you can get the key teaching points across and you are technically competent to successfully demonstrate the lifts as a starting point.
The next point I would look to examine is that of training economy...how much time do you have with the lads in the gym? Are we talking 1 hour twice a week or are you coaching/working with theses lads on a daily? If it is the former you really need to be ensuring you are getting the most bang for your buck training wise...and many will argue that Oly lifts in that case are the best way to go...while others will argue that improving maximal strength should be your highest priority as maximal strength improvements are going to lead to improved power and speed and this will lead to the greatest 'bang for your buck' football wise. I know I am arguing both sides already but I promise to fall on my side of the fence or the other at the end of my ramble.
If the latter is the case then you are on a real winner as you can integrate Oly lifting components and teaching point into your dynamic warm ups and movement preparation work prior to football practice. This will continually reinforce and develop their lifting techniques and they will carry this with them into the gym which will reduce your 'teaching' time and allow you more 'coaching' time.
The whole 'too hard to learn' argument doesn't really hold water for me. You would use that argument to stop you from teaching these youngster how to step/cut properly or how to tackle effectively...as anyone who has coached before will know...this is hard but well worth doing and I would say that learning the Oly lifts are well worth the investment in time.
I could ramble on about this for hours but basically it comes down to this the Oly lifts and all their many and varied variations are all just 'ingredients' everyone is going to put them together differently...I think you really answered your own question...if you find them helpful...that?s good enough for me.
p.s: I know I promised to come down on one side or another...I didn't forget...I just lied.