Look, If I am conducting an ILS on a very windy, choppy day, I will hand-fly it from a long way out in order to get my responses up to speed, so that at around 4-5 miles, I am totally in the groove and able to deal with whatever the wind throws at me. I do NOT take the AP out just before minimums !!! and nor was I suggesting that.
Is it {more talking} really required or just a rule that could be changed ?
You would have to ask Airbus/Boeing, they write the SOPs. Obviously, you don't want a situation where PF does their own thing and becomes a single pilot operation while PM loses SA. You need to keep both pilots in the loop
Regarding practicing hand-flying in poor weather or busy airspace; yes of course you can, but you must remember that you will massively increase PM's workload, and airlines are commercial operations. If pilots violated noise abatement or made errors in busy airspace because they were hand-flying, the chief pilot might have something to say.
Practice in sensible conditions, but never be afraid of hand-flying turbulent approaches.
Better to do so a long way out and get into the groove than disconnect at 400' and only then discover how much the AP was coping !! (This especially applies to Airbus FBW, since you cannot normally see what control inputs it is making).