Okay, there are actually faster ways to grade forum posts for those who don't want to read what students are saying, in context.
1) Go to your grade book, edit the item, pick override all, perform a bulk insert, insert a value, then save. You have just given every student the same grade in less than one minute.
2) (Slower than #1, but you can claim that you looked at their post) Go to advanced search, search for the forum of interest, then simple rate each student's post. You should be able to rate around 10-15 per minute. (This is faster than D2L.)
3) (Slower than #2, but you can look at all posts student by student.) Start like #2, but add the student's name in the filter dialog box. Then you will see all the posts for a forum by student. Using this method, if you leave off the forum name, you can simply grade all of one student's posts across all forums. This method is good for teachers who don't care to grade forum posts until the end of the course.
4) If you really don't care what students say, don't include forum discussions as part of their grade. (i.e., Don't use ratings.) This is really the fastest. There are probably many students who would really like this method.
5) What students would like most, and involves the absolute shortest amount of your time and theirs, is simply to not have discussions.
My guess is that there are probably other ways.
Some LMSs can do word counts. I don't recall if Moodle attempts to do this, but I do recall that D2L might. When students catch on, they will learn that the following paragraph is a great way to get full points.
"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."