He may be the only thing worth watching on it, but aren't the young FBI agents (The Mulder/Scully clones) the supposed leads?
Only Olivia Dunning is an FBI agent, Peter is Walter's son and Walter is in his custody since Walter was in a mental hospital. But I think all three are the leads of the show. And I do think the relationship between Peter and Olivia is closer to a brother and sister relationship than a romantic one.
Personally I really like the show, it started out a bit of an X-Files clone but it goes off in it's own direction late in the season. But they have X-Files style eps. even into the second season.