Harsh marking - is it worth complaining?
I disagree with aparente's suggestion that filing a petition is a good way to get the department to improve.  

Generally speaking, an instructor has a lot of latitude to determine how grades are determined in their class.  You can challenge your grade by a petition, but whoever considers the challenge will be inclined to defer to the instructor's judgement, unless the grading was blatantly unfair or unreasonable (some universities use the standard "arbitrary and capricious"), such that the grade wasn't really related to the quality of the students' work.  A grading scheme that is just "too harsh" or "too picky" isn't likely to meet that standard.

It also isn't really a good way to bring the issue to the attention of the department, due to the adversarial nature of such cases.  If the grade is upheld, as I suspect it would due to the required standard of proof, people may tend to view it as "the instructor is right and the student is just whining".  It will also focus the attention on you personally, instead of on the fact that this is a general problem affecting many students.

I would suggest instead that you mention this issue in your course evaluations, and encourage other affected students to do the same.  Explain the issue in detail and as objectively as you can, keeping the focus on how this affected the quality of the course, rather than on how it impacted your own grade. If the department cares about teaching quality, this will encourage the instructor to work on this.  If they don't, then there is probably nothing you can do about it in any case.