
Occam razor people, Occam razor. Normally the easiest answer is the correct one. I do believe that Adam was crying because his comrades couldn't kill more people
Some say he was actually just lying to Blake here. Because of "toxic masculinity" and all that, he was pretending he didn't care about the deaths of his White Fang brothers and sisters.
But as I pointed out, the simpler explanation is probably the correct one.
Adam has been portrayed as irredeemable, almost pure evil. So it really wouldn't surprise me if the comic writer simply didn't want you to empathize with Adam in this scene.