It is true that asuran fists was an average weaponskill, compared to some other jobs weapon skills ( like raging rush) but it was the best H2H ws ( well excepte final heaven and PUP's nuzul ws maybe). It was still better than GK or dagger WS for example (unstacked). Being an average ws by itself didn't prevent mnk from being the best/scond to best dd at the 75 cap, due to the massive DoT and WS frequency.

Pro Tip: you stack ATK for asuran fist, STR and VIT are only good if incremented by 10. STR+VIT=200, and remainder mix and match with acc and att, was a goot WS build.