They also make the Pro, V, Case-Lite, DP, Fren-L, Scandles, and a few others, so I don't think they're hung up on four letters... but I don't have any idea where they get the names from, other than CaseLite, which is because the light is the case, and Fren-L, which is their fresnel light.
There's a certain weirdness about Lowel, that I can't quite put my finger on. Maybe, if L. Ron Hubbard had jumped from being a sci-fi writer to the lighting business, instead of starting a religion--it would have been a lot like Lowel.