Droid, regardless of whether it’s a mitzvah or not, it is a good thing because:
It is a chessed. You are saving your guests time before shabbos that they might otherwise spend preparing for a meal. It improves your middos, because you are focused on your guests’ needs, not your own. You may actually be fulfilling the mitzvah of V’ahavta L’raiacha Kamocha. You have the ablility to share divrei torah with other people. It improves the guests’ middos because they are focused on being courteous, respectful, and complementing.
These are just a few reasons why it is a good thing. I don’t do things ONLY if I get a mitzvah from it. That’s a very self-centered attitude. I do things that I feel are correct, and G-d would want me to do them, regardless if I get a mitzvah for it or not.