Unless they create emphasis within a parallel sentence, you should look to cut expletives. Look to the right in the sentence, find the agent, and move the agent to the subject place. He became a surly and moody child for several reasons. As a writer you want to eliminate these expletives and establish an agent or state the fact directly. Bill Clinton deserves to be impeached.
Gerunds convert participles into nouns.
They eliminate agents by turning an action that would require a subject into a subject. But if you rely upon gerunds, your prose will become agentless and, perhaps, deceptive. Bowling is fun. Hunting is a great sport. Bowling as many as three nights a week, my uncle had great fun at the lanes.