Yeah... no.
This isn't an accurate statistic at all. On it's own the completion % is meaningless.
I started playing the walking dead, didn't really get into it in the first hour, and haven't played it since. Am I now one of those 2 in 3 players who don't finish games?
A more accurate way of reporting these statistics would be: 75% players who completed roughly 50% of the game's storyline went on to complete it... or 40% of players who didn't finish also didn't advance further than 20% into the game.
Now that would have meant something. You can't report on only one variable - to establish some kind of relationship it needs to be compared against something independent (like progression)
