I'm not sure I understand your point?

Say for example, I'm looking at a freshly cloned repo. There's a first commit and most-recent commit on master - I can identify them with git-log. The problem is that I cannot view the path of commits between these two if I'm only interested in the commits made when the current branch was master (which is generally the case unless I want to drill into a feature branch).

Disallowing merges makes the problem go away but that removes a lot of options in terms of work-flow.