Thinking it over, a lot of canon/possibly canon ships seem to be prospit/derse pairings. Kanaya/Rose, Karkat/Dave, Terezi/Dave, Jake/Dirk. I guess John/Vriska doesn't fit but I thought it was neat enough to mention. Even Sollux and Aradia had a both/"none" moon affiliation.

Out of the 23 relationships that have been canon there have been 12 ships of Prospit/Derse pairings and 11 ships whose dreamselves were from the same planet.  So I wouldn’t exactly call it “a lot” it’s only half which makes sense.