Just to expand upon what other people have said not only does it cause a big explosion which usually kills whoever is firing the laser it also looks almost indi

Just to expand upon what other people have said not only does it cause a big explosion which usually kills whoever is firing the laser it also looks almost indistinguishable from atomic weapons, which are considered a war crime in the Dune universe. Essentially all the major powers have signed an agreement to all hang up and nuke anyone who nukes anyone. This means lasers aren't even a good suicide attack strategy because it may lead to your entire house being glassed