Sudden revelation

I was watching the documentary "A Century of Rugby" last night. It's quite interesting because it has a lot of footage of the "great" teams of the 1970s like the Welsh and the 1974 Lions and stuff. Now I watched those guys as a teenager and definitely absorbed the conventional wisdom that guys like Phil Bennett and David Duckham and Grant Batty were terrific runners with the ball. I think I've figured out their secret. Nobody back then could tackle worth a damn. I watched two minute clips last night that had more missed tackles than a whole TriNations series today! It's not just that tackles are being missed, it's that they are wussy flailing arm attempts at tackles that I'd be embarrassed to make. Now the thing I can't figure out is why, with such horrible defences to run at, they didn't run the ball more.