Continuing your spoilers:
I see two very important sides of this; the first is agreeing with you, in that it really creates a barrier between Rael and everyone else, since it sounds like everyone else either has or will have many biolocks in their life to extend out for centuries, while Rael may potentially be forgotten or never truly valued.
The second, however, is much more romantic in that because Rael won't live that comparably long, his time with the crew will hold that so more significance. After all, knowing he won't live as long as everyone else will make him appreciate the day to day happenings on a much deeper level than anyone else on the ship, and perhaps in turn result in the crew viewing him with a greater level of respect.