Issue I take with DPS SAM is it's defenses will suffer, will likely share maiming gear and will most likely offer little to nothing and like most DPS have little responsibility in a majority of content compared to say a Tank or healer. Kinda like how it's expected for a DRG to screw up and no one will care.

On Tank side it's AP will suffer, will rely on parry to do anything, share fending gear and we will have 4 physical tanks as far as weapons are concerned. What will that offer? Very little. Could say DRK's parry mechanics was testing the waters for SAM.