I write descriptive commit messages because the code I check in is likely to contain a bug. This bug tends to be discovered a couple of years after I worked on the code. By linking my commit message to an issue and having a good explanation for why I've done what I've done, I can easier get into the mindset I had when I committed the buggy code. I find my life gets less stressful this way. I do agree that just regurgitating the files/classes/methods a commit touches isn't very useful. I'll consider ceasing to write "good" commit messages when I'm confident the code I check in doesn't contain any bugs.