Writing a dissertation or thesis is not an easy task. A thesis can have a huge effect on your final transcript. You can ace all your grades but the end, your final project and thesis count for everything.
No matter how good your grades were, it will be all for nothing if you fail to present a successful thesis or dissertation.
A dissertation writing includes research and discussion on a specific topic. It is not like an ordinary essay. You can write an essay in a couple of hours if you pay attention.