I don't see a lot in the gym that bugs me nowadays....
When you first get out of Uni/College and you begin training people it is easy to be idealistic and to take issue with other trainers prescribing exercises that you think are either: inappropriate, unsafe or unsound in some way; and to take issue with gym goers performing exercises that are considered contra-indicated...
However over 10 years in practice, I have realised more and more that I cannot be everything to everyone, and nor would I want to be.
There are, as in all things in life, many ways to skin a cat. And sometimes someone performing an exercise that might for the most part, and for most people be contraindicated could in fact be justified in doing so for a specific performance benefit.
What can bug me though (particularly if I am a little scratchy due to early starts, lack of sleep and 2+ hours a day of training!) is trainers who teach what they obviously cannot do themselves!
There are a lot of training techniques that are GREAT for athletes as part of their power and strength development. The Olympic and All-Round lift variations are great examples of this. And so exercises such as the Power Clean have become staples of athletic conditioning plans. I think many trainers feel compelled to use these exercises with their clients because they are so effective. But simply because an exercise is effective doesn't mean you should teach it!
In fact if you can't teach it correctly you're better off leaving it out...hell a lot of trainers can't even DO IT, let alone teach it correctly - there are plenty of other things you can apply in it's place - and this is even more true where you are not training athletes, but instead weekend warriors. Why diminish the benefits of a GREAT exercise through poor technique and risk injuring your clients? Teaching a great exercise poorly doesn't make you a good trainer - it makes you look like a jack ass!
Sometimes it seems that to call yourself a strength coach the only pre-requisite is to add some complicated all-round or o' lifts into someone's plan...but a power clean does not a strength coach maketh!
I see the same thing with Boxing and Kick Boxing. Trainers use these with their clients because they give a 'great workout'. having trained with some great boxers and boxing coaches I can see the logic in this to a degree...but wouldn't it be great to teach good technique as well as simply giving a good workout? If nothing else proper technique reduces the likelihood of injury...plus it always makes me laugh when a young guy says he's "learning how to 'box'" with his trainer and when I see what they're doing it's like some weird form of Tae-Bo/Aerobics....
...Dude you're not boxing - you're dancing....badly!...
If I have a client who wants to do something, or who needs a type of training that is outside of my realm of expertise, I hand them on (for that part of their overall conditioning) to an expert. I am blessed to be working with a great team of Strength Coaches at Human Motion who all have a depth of knowledge that is unrivalled...but like all true experts they know their limitations and don't try to be 'everything to everyone'. But amongst our team we can cover all of the training bases.
To my mind you have two choices as a trainer. Either be a damn good trainer doing the things that you do well OR expand your knowledge base so that you can teach...and of course DO the things that you are expecting your clients to do.
If you want to teach boxing or martial arts then get into the gym or the dojo and get some instruction from an expert.
If you want to teach advanced lifting techniques then put yourself in the shoes of a lifter and learn how to do it from a qualified coach.
Trainer - know thyself....and don't be content to look like a jack ass!