How many times could one swing a large two-handed Axe and brutally murdering a creature before they get tired and start doing worse? Combat classes can go out all day long and gain SP in a variety of ways and the only thing barring them is fatigue. Gatherers can do that but the difference between SP gains of both are tremendous. The SP gains don't even need to be equal, just better than they are currently.

Also Peregrine I agree with your point that the dev team shouldn't listen to every "popular" idea but you could have presented it in a less offensive manner.