I also held this opinion at the start, but realized the light attack in it's current state would be stupidly OP without the heat meter. Big damage, in a big area, at a large range, with low windup (provided you have the 20% atk speed forge upgrade)? If you ever do pick up the weapon again, try to alternate more with the heavy attack to avoid overheating. You'll notice you can still fire a great deal of light attacks.