Another way to look at it this (re Gordon) is how his teammates were doing at the same time. He was only the feature back his senior season. He shared carries with Ball (the #1) and White his freshman and sophomore seasons (Ball or Ball and White were the feature backs), with White and Clement his junior season (Gordon and White were evenly split as the main backs--White had a handful more carries than Gordon), and with Clement and Ogunbawale his senior year (the only season he was truly Wisconsin's feature back). On the one hand, why wasn't he the feature back sooner if he was that good? On the other hand, because Ball was (and may be again) and White is still an NFL back, so no slouches themselves.
His 8 ypc his senior year were significantly better than Clement and Ogunbawale (the latter being a frosh, I think, so best not to read too much into that), more than a yard per carry better than White his junior year (with approximately the same number of carries), way better than Ball and White his sophomore season (at 10 ypc, but on way fewer carries than either of those guys--Ball was at 5.1 as the feature back, white was at 6.4), and as a frosh--unsurprisingly--he was about average for the team.
Wisconsin backs get dinged for being "system" backs because Wisconsin typically has beastly offensive lines that open big holes. No question Badger backs--and Gordon--benefit from that. On the other hand, Gordon's production was substantially better than his Badger peers, both over his career--which included other professional-level Badger backs--and relative to other Badgers who had similarly dominant offensive lines (think the Ball/White/Clay years).
Gordon was really, really good. Best #25 ever? I voted for him, but there are a lot of good options.