I find the openess of Bruichladdich on this matter to be quite insightful. They have championed the cause of the consumer and been very "anti", much to the chagrin of the SWA, "finishes".
If done properly, such as Bowmore's finishes, then I fully support the distillery's use of wood finished casks. Bowmore clearly indicates that their Darkest, Dusk and Dawn are first aged for 12 years in "traditional whisky oak" (read: bourbon casks) and then finished for 2 years in the Sherry, Bordeaux or Ruby Port casks.
Conversely, many whisky makers, as has been recently brought to public light by Bruichladdich, are using increased pressure and/or temperature to "finish" the whisky in a nondescript amount of time. This method is as disturbing as the addition of caramel coloring and useless chill filtration, IMO. There can be no doubt that the more "commercial", large-scale producers utilize these methods to make it more cost effective. One has to wonder if Macallan, Glenmorangie and, now, Balvenie can really put out as much whisky as they do with "wood finishes", while maintaining quality standards and utilizing good aging techniques. Frankly, I don't think so.
I think that wood finishes have been both detrimental and good for Scotch in the view of Americans (I am one, BTW). The softer, sweeter styles appeal to the American palate, which has bolstered the consumption of Scotch in our primarily mixed drink, rum and bourbon consuming country. It is not unusual to walk into a bar and find Balvenie, Glenmorangie or Macallan on the shelf, while finding good, "nonflavored" single malts is significantly more difficult. The detriment comes in the form of mishaping perception of Scotch. Working in the liquor business in the US, I have found, most often, that my customers have become accustomed to these tastes and when I recommend something more traditional in taste, they often find it displeasurable. It is similar to vodka's heavy marketing toward "mixability". Unfortunately, very few people, at least in the US, find vodka as a spirit that can be enjoyed on its own and, most often, utilize it in mixed drinks. I truly hope that Scotch's path is different. This push toward heavily-marketed, sweeter styles of Scotch, has eliminated customer desire to enjoy Scotch's diversity and more traditional flavors.
While I initially viewed this as a good stepping stone for introduction to Single Malt for the inexperienced consumer, I now must take the view that it prevents the consumer from ever truly knowing Scotch's true persona. Additionally, "wood finishes" are often used to cover up for poorly distilled spirit, or mass distilled spirit, which again leaves the consumer in the dark.
I think that wood finishes have the potential to be superb, as long as the truth is known with regard to age and method. However, due to a great deal of peer pressure from the SWA, I fear this will not be the case very soon. Once demand for honesty is pressed from the Scotch consuming public, we may truly discern the true abilities of a distillery and its Master Distiller as well as the benefits of wood finishing.