Not sure how to define this route. For the ordinary Moskovites, HK is an expensive city to visit. Nice beach and club, yes. But it'd be much more fun to get smashed in Nha Trang, Phuket, etc (Plenty of nonstop flights too) The ultra-rich prefers Spain, southern France, London and Dubai.
Cathay would need much more comprehensive codeshare with S7 to make this work. Remember when AB was still around, it was convenient to fly HKG-DUS-VCE/VIE/TXL? If CX & S7 could replicate that and give some coverage to central and southern Europe, that'd be great.