I think its fine the way it is. There are a few people that have insanely long names, what of it? If you don't want to invite them (because you are too lazy to ask them, or look it up, or memorize or write down their name), don't. Just that simple - leave it to choice. However, be sure to tell them you are too important to be bothered with their name so they can truly know they didn't miss anything by being in a party with you.

It's hilarious; this vocal minority crowd on this game that screams, "I want things to be easier for me, so take away the option for others!" I detest this attitude in life and I'm not fond of it in my entertainment either.