Nah, I don't agree with that at all. You're saying in universe Batman was wearing a one piece rubber suit that he couldn't raise his arms or legs in? No way. As far as the film's intention goes, Batman wore segmented pieces of armor over a suit. We see this in Returns when Catwoman is feeling around his armor and finds as a weak point to stab him in. Just look when Bruce stores it in the armory when it's not in use. You only see the armor, not the sleeves or leggings of the undersuit.
So clearly the in universe explanation isn't that it's one piece as it was never implied as such like the figures. Hot Toys only did it because that was what they did with the TDK OC Batman, TDK V1 Batman and DX 02 Batman at the time. That was all they knew. Hot Toys made a one piece rubber suit because they were lazy, plain and simple. It was fine in 2011 since it was the first real Keaton Batman figure in decades, but in 2015 with all the innovations they've achieved with their collectibles? Returns could have and should have been more.
I don't mind museum style, arms at their side poses, but they're capable of making it much more poseable, not to mention more accurate, than what they've given us. Slightly raising his arms to the side and bending his arms doesn't cut it. These are great looking figures, but they could be so much more. Having it be separate pieces wouldn't even be hard for them to do. It would be more accurate, the fit of the suit would be better, it would have more possibility/movement and would look really snazzy. I don't see how anyone would be against it.