But how come?
Supporting people is rather easy actually. Being compassionate, caring and listening the other person and being supportive is generally rather easy and oftentimes just words are enough to encourage or console them. That stuff is so easy it can be even faked on autopilot without any effort.

But at the other hand, taking advantage of others/exploiting them just feels bad and even if it's possible to get used to it. It's kinda exhausting to constantly look over ones shoulder for the inevitable repercussions from the person being exploited and to avoid being exploited by anyone else?

Even if taken from the perspective of trying to exploit people. Helping them become better is a more profitable long term investment.