Perhaps so, but Lincoln Spector makes a rather good argument for sharing passwords with others in certain circumstances. He writes, "No one stays healthy forever. At some point, your loved ones will need access to all of your accounts. You can make that job easier for them."
Indeed, after you are gone, who is going to be able to access your bank account? Your E*Trade account? Your BitCoin wallet? Or who can post an article to your personal blog announcing your demise?
For years, many of us have kept records in a safe deposit box and told our spouses or children or lawyers where the key might be found. Lincoln Spector suggests we need to do the same for our digital properties.
You can read Spector's interesting article in PC World at http://goo.gl/JJ7bhj.