I think there's more to it than that. The top 3 rushers (Singletary, Moss and Allen) had very respectable YPA at 4.4, 4.3 and 4.1. So I think that would suggest the line is capable.
However, I think we would agree, the rushing game didn't pass the eye test. I think some of that had to do with predictable runs, unsuccessful runs when we needed them and an overall lack of commitment to running.