Effect of vibration on wine quality
One of the effects could be that vibrations increase mixing on phase boundary between wine itself and air above it. 

Other thing is that vibration are generally not good for crystal growing process (instead big and nice monocrystals one gets polycrystalline solid).  Usually you can find nice crystals of tartaric acid in the bottom of bottles and barrels. I do not know chemistry behind it but certainly it will change taste of the wine if the tartaric acid stays longer in wine (slow crystallisation) instead of falling rapidly out of solution when you shake it.

Of course if there is still a sediment earlier during fermentation, certainly that will be not good if this mixes with clear wine.