I agree with your lecturer that many good essays are based on an argument/debate. I would be far more interested in reading an essay which gives at least two different viewpoints, shows an understanding of both/all sides but makes it clear which opinion is that of the writer and argues that viewpoint well.
I don't think it matters which topic we would prefer. You need to choose the one which you find most interesting and engaging and the one which you will be able to write the most convincingly about.
Edit: I apologise for the bizarre formatting of the quote. I have been trying to fix it for over 5 minutes and getting nowhere.
Student or Learner