True there is a lot more broken - the actual front wheels in FH2 don't move very much either.
I think decent replays are a key element of the game, specially for those of us that enjoy making videos of interesting races etc.. It detracts a lot from the actual game play, as part of play value is simply kicking back and watching a great race replay.
The thing is that this was not a bug during the first 30 days or so of FM5 - it appeared after they patched the 270* vs. 900* issue that was happening.
It is directly related to the use of a wheel during a race. It appears the game does not record the steering telemetry if a wheel is used, so there is not data to read during the replay.
If you use a controller, then no such issue.
Ghosts in replays also used to work way back in the beginning of FM5.