Comment by Rimuru sama on Tensei Goblin dakedo Shitsumon aru? - Chapter 19

@Rimuru sama  Generally speaking, the goal of killing someone in most other stories is to prevent trouble later.  In this story, trouble is created if he kills them especially since he has an absolute surefire way to keep them from attacking a 2nd time due to his skill.  He can also extract whatever information he wants without torture as well as turn them into his allies through subjugation.  

It's not that he's a "pushover" it's that those other MCs didn't have an all-powerful skill like he has.

@Rimuru sama

@Rimuru sama  If he kills a human, the diplomacy he has been building could be destroyed. From the humans’ perspective, if the goblin kills a human, it would be seen as a clear sign that he has broken the diplomatic relationship he has been carefully establishing, and that could potentially trigger a war.

That is why he deliberately chooses not to kill humans. His actions are calculated to benefit the goblins in the long run. It is similar to what happened with the bet he made with the Count. When he realized that he had lost, he did not simply react emotionally or accept the situation as a defeat. Instead, he guided the situation in a way that ultimately created an outcome that benefited him and the goblins. His actions show that he is constantly thinking several steps ahead, using diplomacy and seemingly unfavorable situations to achieve his larger goals.