Are the weights in the olympic bar,if it is than is ok to just leave it.
If plates are all over the floor,than yes he need to put it back on the rack

It's understood already.

So if ever you open a gym,use that sign you propose.

so much this.. once i was waiting for a guy to finish his set and i waited for him to put back all the plates on the rack..and i put back the exact same weight back on it... totally waste time lol

I disagree. Imagine 1 idiot who deadlifted 5 plates (220 kg) for a few reps and once done, just leave the f*cking bar and the plates on. It will be a royal pain in the ass to remove the plates if you want to use the bar for something else. Note that this goes the same even if you're only deadlifting squating benching 60 kg or 100 kg or whatsoever. you picked the bar, put on the plates on, lifted it. Once done, take off the damn plates and put them back. Nobody cares how much you've lifted so no need to leave the bar and those plates hanging there.

Not every gym has a deadlift station with extra oly bar to be used. my gym just have enough bars for the bench press stations and the squat rack. so you're gonna need to borrow the bar if you want to do deadlift. and needing to take the weights off every single time either to setup and do the deadlift, or to bring the bar back to the original place can get annoying.

I've never had a problem with people not removing their plates cause everyone's working weights are my warm-up sets, be it 50kg, 100kg or 140kg. Lightweight.

However I ALWAYS rerack my weights because I know no one can lift what I lift.

Complained a few times before. No Action taken.

I believe its a common courtesy to remove the plates once you are done for others to use since you are sharing with them. So yes, despite having idiots in the gym, I still use my common sense to unrack the weights once im done using the equipment.

I don't see this happening in Old School Gyms. Only in 'Fitness Centre'

To me it is common sense and courtesy to remove the plates from the bar after you have used them. It would be so much more convenient if someone else wants to use the bar elsewhere. Imagine the bar with 200kg worth of plates on it and it's sitting in the squat rack and I want to use the bar for deadlift. I'm going to have to remove all the plates before I can even take the bar down. Re-rack all the plates after using. Don't assume the person after you will be using the same weights.  I don't see how this is so hard to understand.

well said.....unfortunately this isn't the case