Only the CMD can fly it.
Why do some Airlines adopt that policy? As an FO, I was allowed to fly into LCY after a Sim Session with EFATO's and then 5 approaches as PNF.
If you are tought properly, it isn't anything to worry about as long as you are prepared, just a bit interesting with a gusty southerly......
Surley if an FO is based at LCY and is part of several approaches per day, he should be able to land the a/c as well as the CMD, in some cases better looking at some of the landings.