Many SMW drinkers would (pardon the pun
) say that excessive (though quite subjective to the individual drinker) oak indicates a flaw in the whisky and it has been left in the cask too long before bottling. Others, however, like it. The same aplies to wine. We see numerous "unoaked" vattings nowadays to suit differing palates.
The effect of oak on spirit is a mysterious thing and the flavour generated by the interaction of the two is still unfathomable. Every cask has its own characteristics and we should not underestimate the skill of the master distiller in identifying when a cask is ready to be used.
American oak and European oak are completely different animals of course and distilleries use both to create a particular house style. What is clear, however, is that the distiller is looking for balance and oak/woody notes are part of the mix.
In this day and age and with profit and loss playing such a major part in whisky production, I suggest that if you get oak on the palate, you are probably meant to. Look at the efforts of Bill Lumsden and Glenmoragie to get the right wood to hold their whisky. If you get oak in Glenmorangie, it's because over 10 years of work has gone into making sure it's there.