There are plenty of meaningful suicides in history, where agents killed themselves before they give up secrets that can hurt their countries, or went on to fight hopeless missions for some essential tactical goal. Assisted suicide for terminal patients is one way people can retain meaning and freedom in their last days.
People who want to die with dignity are not trying to make a point about how the world should be run. People who strap bombs to themselves or take down planes, are, but their point should not be taken seriously; they don't intend to live here. You can make a point with your death, suicide or otherwise. You can't expect it to matter to people who are still alive.
