You will find that your future is filled with busy people who will read what you write as quickly and with as little preparation and attention as they possibly can. If what you write is not immediately, transparently clear, your words will be filed in the "get back to this if there is ever time" pile. (Spoiler: there is never time.) This has consequences:
- Say what you mean.
- Mean what you say.
- Get to the point.
- If there is a standard way to say what you are saying, say it in the standard way. The mental cost of parsing standard forms is much lower than parsing novel forms.
- Produce valid sentences. The mental cost of parsing malformed sentences is much higher than that of parsing valid sentences. (Example of a malformed sentence: refusing to put equals signs between a sequence of equal things. As a result, that sentence no verb.)
Let's express the same idea in terms of grading: The grader reads through your answer until they can no longer see how you are making progress towards a solution. Based on the fraction of the (or a) correct solution you have produced by the time the grader aborts their attempt to make sense of your answer, a grade is assigned. The more harried the grader is, the less hard they will attempt to overcome deficiencies in your answer. The same five points apply. Unless the class actually is Creative Writing, the grader will not absorb and reflect on your answers; if they don't see that what you are writing is correct, it's wrong.
Let me tell you a story: I teach math. I have a one page "How To Write [subject]" that I provide every semester. It contains useful advice: "1. Draw a picture. 2. Label the picture. 3. Write top-to-bottom, left-to-write. ..." When I share this with my friends that teach at other Universities, they cannot stop laughing. "You have to tell them to write top-to-bottom, left-to-write?" Yes. Mysteriously, there are students in college who have not yet noticed that all of the long form textual information they read is in the same format, so they write their math in small islands randomly scattered on the page. If I had infinite time, I would go to the trouble of figuring out what order their answer is to be read and piece together whatever argument they were trying to make. However, life is short and this is not the only problem to be graded -- once the amount of effort to make sense of the answer exceeds the time available to do so, it gets whatever grade it gets.
On changing grades. I have done this. On a particular problem, students were to compute the surface area of the non-circular part of a cone. One student bafflingly had too much area but their computation was scattered around a diagram, so I it was not clear what they were doing. (Actually writing, "First, we compute ..." and "Then we find ..." would be great. It would be as if the answer were written in the style that one would answer the question in direct conversation. But for some reason students refuse to construct their answers in this fashion.) Several papers later, I found another student who had the same incorrect answer but they had organized their answer so it was possible to figure out that they had included the area of the circle. "Aha!" said my brain, "that's what that previous student did." I then went back and adjusted the grade. (The student had demonstrated the skill "compute this area", although they had obfuscated this fact.)
I require my students to write identities in columns -- this has a number of benefits. On the first assignment involving identities, I put friendly reminders that identities are written in columns and indicate with boxes and arrows where the student's work should be. On the second assignment, I just refer to "How to Write [subject]" by item number. On the third assignment, refer to the item number and take off a few points. By the fourth assignment, I just write a big, red "X" on answers that are not in the form that has been called out on three prior assignments, and both repeatedly demonstrated and called out in class.
No one will force you to drive on the correct side of the road, or not run with scissors. However, the action of failing to conform to conventions will have their own consequences. With as little context as you have provided for the instances of grading that you do not seem to like, it is difficult to draw any conclusions. Nothing you have written is inconsistent with things I have done in my own grading. Perhaps you and some of my students think that I am mean for doing this. But this is false. If I were mean I would tell my students: "I look forward to the future for my children, who can write complete sentences respecting margins and correctly fill out forms. They will have an easy time competing with you for resources. Why? Someone with a pile of 100 requisitions, or 100 proposals, or 100 resumes is not looking for a reason to keep every document; they're looking for a reason to discard them. And 'can't follow simple instructions' is an excellent reason to discard."
Perhaps you feel I am harsh. Excellent. Get out there and change the World so that what I have said is no longer true. I recommend that you find valid solutions to the World's problems and that you explain them clearly and cogently so that everyone can benefit from your wisdom. (Also, keep it short. Until all our problems are fixed, no one has time for long, complicated explanations. If you can't, you're just going to get the listener's equivalent to a big, red "X" -- they stop listening, switch channels, un-friend you, drop your message in "Spam", et al.)