Goal-line packages are different...but that type of specialty offensive formation should be reserved almost exclusively for goal line or short yardage situations, not on 1st and 10 from your own 20, or 2nd and 7 from their 45.
Remember, if we take out a FB for an extra WR, then the defense must respond by bringing in an extra DB and removing someone from their front 7. So the big guy in the box that the FB would likely be blocking is no longer there anymore(it's now a skinny guy opposite Manny Sanders instead).
I just think it comes down to our o-line doesn't win their 1-on1 matchups. If they can't win their matchups, the formation doesn't help/hurt matters.