Somewhat agree/somewhat disagree. Products don't last forever, but the large open source products like Drupal and Wordpress have been around a fairly long time - long enough to instill confidence in my boss that they will, more than likely, continue to exist in the future. I do agree with your second point. But my point was not necessarily about my personal opinion - my point was that organizations are often concerned about this (e.g. my boss) - and that makes it difficult to commit to a smaller, closed-source or hosted vendor.