it's a bit odd, I agree, but not totally weird. Laos was part of the French colony called Indochine, which included Vietnam.
The French have been gone for years, but French influence is still very strong - more people speak French than English, for example.
It is a very poor country, and not high on the list of tourist destinations, at least, not yet. BUT - the French love going to tropical countries where their language is widely understood, and it's certainly exotic.
There could be enough tourists for a weekly flight, maybe, but I think most Europeans would choose it as an "add-on" to other places, such as Vietnam. I doubt there's that much traffic originating from Laos.
Still, stranger things have happened.