Fighters also have martial weapon proficiency, so they atleast have the option of a stronger range offense than the monk, even if it is just them sinking just over 1000 gold into say a +8 strength master-work composite long bow. Add splitting to that for 18000 gold and you have yourself 8 shots, much better than the monk with a crossbow.
Then also they have a larger variety of weapons, high up on that list would be the spiked chain, as well as a variety of weapons with better criticals than the monk has.
Also the fighter has D10 HD to a monks D8, which when comparing tanks still has some value.