Actually it is not intentional. We do not have any connection to Lua. The name "Luna" was used from the beginning of the project, people started recognizing us with it and we simply love this name so it stayed with us.
If such confusion would be often, we will change the name, however, we've got few comments that this name could be confusing but in fact nobody ever confused it.
We are still open to change it and are actively looking for any kind of replacement. If you have any idea of a name that would be suitable for such a language, I would be more than interested in hearing it.
Moreover, I just opened a thread on our forum to discuss names propositions. If you've got any ideas, please share them with us! :)