i just made a stripped down tree on here not to long ago, downloaded it and added it to my FTDNA account. At the moment I dont have a program for my computer. I have a very well researched tree on ancestry that a few people work on. We would not be able to work on it together if the info was only stored in my computer. Ancestry is convenient if you have a few people that need to get on the tree that live in different locations.
And I agree with you that people should research and prepare before they DNA test. DNA can reveal things that people are not aware of and may shock them from ethnicity to NPE or unk adoption. DNA is like opening up a surprise package. There are those people who think everything they have been told about their family is gospel so they believe it and dont keep an open mind that DNA might prove the gospel to be untrue. Paper can lie but DNA can tell the truth.