I agree with the premise, that numbers do matter. I also think it's perfectly legitimate to question the low completion percentage (and/or have a debate as to what factors play into it), but I have to say, through this whole process I've been surprised at how everyone seems to equate this stat with accuracy.
I don't think Allen is inaccurate. I do think he needs to complete more passes, but I don't think accuracy is the culprit. I think he needs to keep progressing in his understanding of NFL defenses, needs to take the easy yards when they're there, and hopefully have more plays at his disposal that emphasize the short game (it worked quite well with an 80% completion percentage to kickoff the Lions game).