People are drawn to the idea of mechanistic ways to understand and describe code. If true, think of the ramifications for efficiency and productivity!
I agree that a metrics for "code goodness" is about as sensible as a metric for "good prose." However that doesn't mean metrics are useless, just perhaps misused.
For example, extreme values for some metrics point the way to possible problems. A 1000-line-long method is probably unmaintainable. Code with zero unit test code coverage probably has more bugs that similar code with lots of tests. A big jump in code added to a project just before release that isn't a third-party library is probably cause for extra attention.
I think if we use metrics as a suggestion -- a red flag -- perhaps they can be useful. The problem is when people start measuring productivity in SLOC or quality in percentage of lines with tests.
