Until March, 2014 I never, ever shared my passwords with anyone. Banking, Facebook, email, you name it and I wouldn't share it. On 24 March, 2014 my wife of 29 years died suddenly from a rapid onset of cancer. From "Gee, I'm not feeling so good" to GONE was less than two weeks. The last thing on my mind sitting in the hospital with her was getting all of her accounts and passwords.
During our 29 years of marriage, I was in the U.S. Air Force for 20 of those and traveled quite a bit. She set up online bill paying and I never knew about a lot of the credit cards she had. Once she was gone it took close to 6 months to get everything straightened out with accounts that I had to pay but couldn't get logged into. When I would call the bank/credit card company/etc I was often given the response of "she needs to let us know you can handle her accounts before you can change the password". One company wouldn't even accept her death certificate as proof she wasn't here any more!
I recently got remarried to one of my late wife's best friends. The first thing we did was put all of our accounts and passwords into KeePass. Security is good, but peace of mind for your loved ones it important too.