As previously mentioned, the term currently seems to be indigenous to North America, rather than both sides of the water, so I doubt that the shape of the tip of a cricket bat has much to do with it. Still, the possibility remains that this is yet another archaism which survived in America while being lost in Britain. Commendable illustration, though!
Having spent many hours working on roofs myself, I admit I came up with a theory regarding the origin of the term (to do with the shape and position, and the insect’s traditional association with the hearth, rather than a more proper linguistic analysis), but that was merely the sort of idle speculation in which one engages while carrying out the more tedious aspects of a job.
The Carpentry Way blog has a very interesting, yet still inconclusive entry on the topic.