"gitk" and "git log --graph": Strange behaviour with --follow

I found something very strange in graphical history tools "gitk" and
"git log --graph" when used with --follow. In Git repository compare the
following:

  $ gitk -- utf8.c
  $ gitk --follow -- utf8.c

The output of "git log --graph" is somewhat similar:

  $ git log --graph --pretty=oneline -- utf8.c
  $ git log --graph --pretty=oneline --follow -- utf8.c

All I can say is that the output is not intuitive at _all_. Almost all
the commits are in separate history lines.