Sometimes minimal information is better than extrapolated information, especially when the extrapolation mentally painful to read and has decent probability of being wrong with inaccuracies that waste people's time.

Also:

1. It's often a premature extrapolation from diffs and tickets which you could probably generate later, at need, and likely with even better results.

2. If those commit messages can ever influence future work, then it's just carcinogenic cargo-cult cruft. Pruning outputs (future inputs) is important to prevent weird unwanted drift.