Because they are a necessarily evil in the eyes of Garp.
Whenever the topic revolves around Garp and his relation with the CD's then supporting them is a
necessary evil but when Admirals do it they're the dogs of the CD.
Remember all the shit talking when the most radical Admiral Akainu said that the people who suffer under the warlords are a necessarily sacrifice to keep the system running ?
What I'm asking for here is consistency.
If Garp is what I'm assuming written to be a good hearted person, he cannot turn a blind eye to all the suffering that's surrounding him which is caused by the people that give him his paycheck. They're literally forcing slaves to carry them.
Garp was in the position to do something but he didn't while guys like Dragon and Fuji did. I'm fine with that since I stan Akainu of all Marines but people should stop pretending like Garp is any different to the other Top Marines.