Already had that discussion on FB with a guy with whom we both are longsword fencers, where crossbars are way more common than on lightsabers. This lazor crossbar just opens up a new batch of opportunities for your opponent to make your own weapon kill you, while does not protect at all, as lazor is not coming out of the hilt sideways immediately, only after a short protrusion.
The "beam protruding too far" argument has been very common, but consider how many lightsabers have "shrouds" that extend past the emitter. It's possible the actual beam emitters are recessed into the hilt and you're just seeing a ring of material to protect the wielder's hands moving up and down the grip, especially when bending at the wrist to do all those theatrical moves (as demonstrated in your sig). Should a blade come down on them, it'll cut away at the shroud, but still hit the beam.
You can probably expect the character to have some signature move involving superior strength or some cheap force trick to push into opponents during saber locks and stab them with the crossguard. And you're right, it might also be the cause of their own death later on.
Considering how common cho mai (slicing off hands) is, it sounds like a good idea (by movie/Star Wars/J.J. Abrams logic).