How can you change a bad course run by somebody else?
I commend you for caring about these issues. When you have a permanent position somewhere, I hope that you will push for the sorts of improvements you described.

For the moment, you are in a position of essentially no power, and it is unlikely that anyone will listen to you. You tried the only potential solution at your disposal: you raised your concern to the academic in charge, and you found he doesn't care.

As such I recommend that you do the best job possible within the limits of your authority, try not to make any enemies, and try not to worry about this much. If a similar situation occurs later in your career, when you are likely to have more clout and authority (and possibly less pressure to publish), you might push harder for change.