Some people seem to forget that not too long ago battleships had rotating turrets, and the turrets had masses up to 2000 tons (like in the Yamato class BBs).
I do not believe anyone has forgotten that. It's just that on aircraft carriers, space and weight are at a much greater premium. Typically, such apparatus have not been deemed necessary and were therefore not used.
If something is useful why not take advantage of it.
No arguement there. Clearly, the Russians felt it useful, therefore they designed it into both of the vessels of the Kuznetsov class carriers. The Kuznetsov and the Varyag, which has become the Liaoning.
A simple turntable that can handle 50+tons can be robustly designed and doesn't have to be that complicated (look under a lazy susan).
I do not think the issue is so much regarding its complexity...though I may have used that term. The issue is simply that it is additional heavy equipment where none had been deemed necessary before. I understand all of the issues about the size of the hanger on these vessels and the size of the SU-33/J-15, but I also believe they could, with training and appropriate SOPs, transit in and out of the hanger wthout a turntable.
Clearly the Russians felt it was much easier and time saving with the turntable, and it probably is...therefore they have it. And by extensions, the Chinese got it, and when they looked at the dimensions, and the pros and cons, they determined it was worthwhile fpor their operations and so they refurbished them along with the other equipment.
Good for them...I am sure they will get a lot of use out of it as they move aircraft in and out of the hanger, and as non_name indicated, if it breaks down, then they will just manuever in and out of the hanger without it.