Just as the OP has posted information against the practice of tail docking, there are numerous articles and references regarding the need for tail docking. Below are links to several of the many articles I found with a quick search. The last link seems to be the most unbiased article, giving reasoning for each position.
Although, I do have friends with yorkies not docked and they are beautiful yorkies with their tails, my preference, given a choice, is for docking.
http://netpets.org/dogs/healthspa/case4dock.html http://www.britfeld.com/tail-dock/facts.htm http://www.professorshouse.com/pets/...l-docking.aspx