I've yet to find an example in real racing where contact is punished by Time Penalties. Disqualification, yes. and I'd expect that.
Same goes for leaving the track. If you overcook a corner in games that punish for such things, you are doublely punished.. once for leaving a track and again for the speed and recovery. Its rediculous and takes the fun out of it.
If you stray from the predefined "racing line" you are punished, the only way to overtake is to take the straights and better handling can never win, because as soon as you've taken a position in a different line either by breaking early or late depending on the corner, you are instantly in the wrong, so the "correct line" driver can ram you with impunity even though this is not how it works in real racing.
If they did include it, even for just multiplayer games. Then it'd better be an option, and I'd put money on 90% of people leaving it off as the wrong person gets punished way too often.
Time Penalties for collisions and leaving the track are the worst thing thats happened to racing games for years, LFS is a good example of how it should be done if you want a non GT perspective.