Piccolo isn't a loner either. His family just happens to all be DEAD!
Piccolo's family was larger than most realize. Katas was his grandfather on Namek. Then the Nameless Namek was his 'father' who split himself into King Piccolo and Kami. Tambourine, Cymbal, Drum, and Piano were his mutated brothers. King Piccolo was his 'father'. Since he fused with Nail, all the other Namekians that Guru hatched became his brothers and Guru his secondary 'father'.
So since he fused with Nail, not all of his family is dead. Dende would be family by fusion. All the living Namekians would be.
*knows too much about fictional characters*