This obviously makes the game easier. However, I wonder if just enables you to get a few more strikes and spares, or if it makes the game way too easy. Have you tried this variant and what were your findings? (I'm assuming Sackson included the original rule for a reason beyond theme, so what are we 'breaking' here?)
Based on a number of additional plays, I haven't seen my scores increase by more than a couple of points. I'm still in the 120-125 range usually.
I suspect that Sackson made the first ball card rules they way they were just to make the rules simple, no middle, and no back row.