Is it justified for a teacher to refuse your project proposals just because he wants something unique? I'm new here and am not sure whether this is the right place to post such a question or not so rather than downvoting just tell me I'll move the question (as I don't want to be banned for having low rep).
I'm currently in my 3rd semester of university majoring in Computer Science and this question is related to a course I'm taking - 'Data Structures and Algorithms'.
A little bit about the teacher -&gt; graduated from the same university in which I'm currently studying last year and was hired to work here
So, the situation is that we have to submit a project (GUI based application made with Java and JavaFX) by 2nd January. Now, here are the problems:
The teacher demands we

we implement every data structure we use from scratch (I have heard this is standard for this course).

only use data structures he hasn't taught us and that all our projects should have unique data structures. Basically, no two groups/individuals can use the same data structure and as you can imagine this will lead to some people being stuck with highly obscure data structure whose implementation or ways of implementation either might not be available or not clear for the person to understand.

use as many data structures as possible. I researched online on a few websites and found out that data structures are important but they are only a small part of the project there are a lot of other things.


As if that wasn't enough of a problem, he rarely responds to our queries on discord or through emails and the upper management doesn't listen to us.
I have also proposed a few project ideas but they were all rejected because there weren't enough data structures used or he didn't want us to use that data structure or some other reason. A few of these were:

Text Editor (not enough data structures).
Sudoku Solver (overused).
Any project that used stacks to implement history and backwards and forwards navigation (don't use stacks).
Todolist (too small project).

Now, I ask is it justified for a teacher to do such things just for getting a truly unique project?
We have barely 3 weeks left to start and finish our projects as not even one of use has gotten their projects approved yet.
EDIT:
Something happened last night, the students that were doing projects in groups collectively decided to not bother getting their projects approved anymore and are now going to go with whatever they want to, they will still use data structures but they are no longer going to strive to meet any of his criteria. They were extremely frustrated and being on the end of their rope they have decided on this and are saying that they will deal with it on the day of the evaluation.
It sounds like the standards are pretty high. It sounds like the instructor doesn't want you to be mediocre. It sounds like they are demanding some creativity.
Those are good things, actually.
It is hard to judge whether the standards are unreasonable or not but you would benefit by meeting them.
Are you permitted to brainstorm with other students? Do that if allowed. Have you asked for ideas from the instructor? Have you tried to take any of your original ideas and modified them to come closer to the standard? Alternatively, have you taken any really hard problems and tried to whittle them down to something that is doable and meets the standard?
It's good that you aren't being singled out, also. The farther you go, the higher the standards you will be expected to meet.