In American football, why is scoring a "safety" so called?

In the early days of the game, before the introduction of the forward pass, games were usually low scoring affairs. Suppose a team was leading 6-0 with a few minutes left in the game.

Rather than risk a fumble, or having to punt from the end zone and risk a blocked punt, the team could down the ball in its own end zone. The ball would then be moved to the 25 yard line, and punted from there. It was called a safety because it was considered a safe strategy. Nowadays you will seldom see an offensive team deliberately take a safety, but in the old days, before the rules changed, it was used frequently.

https://en.wikipedia.org/wiki/Safety_(gridiron_football_score)
http://bleacherreport.com/articles/1184750-25-craziest-football-terms-and-where-they-come-from/page/6