Is it cruel to kill cockroaches?

'But as a team, we collectively killed the cockroaches that appeared in our room on our last day...ScreamDisappointed Onward to Berlin and fast. Bus'

A friend wrote this to me. What do the emojis and ellipsis mean here? Is this a kind or cruel thing to write?

Is it cruel to the cockroaches? Does the author of this pose care about the cockroaches they killed?