It's an interesting argument and always will be. Each case is different;
It's only interesting in the context of the race. In itself, it's a tedious subject for discussion.
As you say, it didn't matter today because Nibali wasn't attacking the yellow jersey. I think that's why I found it admirable rather than unsporting.
I love Nibali's attitude to racing. In these days of W/kg and racing by numbers, you don't hear people talking about panache so much, but he has it in spades. (As does Contador, which is why I have grudging respect for him despite his past.)
Bardet too. What a fun young rider he is to watch. I just want to pat him on the head and ruffle his hair and tell him what a clever boy he is. Arthur Vichot may have the cheekbones, but wee Romain has the racing chops.