Count me in as another one who hated writing journals. Maybe I was in the minority, but I never did it, and then had to fake writing in the journal the night before, using different pens to make it look like I was writing at different times. I think the reason I hated journal writing so much was I didn't want to write my observations down. I made too many of them, I didn't know where to start. My brain was always observing, and not only observing but remembering.
It's something I have taken into my adult life as well. As an actor, especially in drama school, when we would be working on a play and my director gave me notes, I wouldn't write them down. Writing things down doesn't help me remember them, and it also distracts me from the actual advice being given. I worry too much about HOW to write the notes, point form, full sentences . . . plus my handwriting is awful. I now know to go up to directors at the start and explain to them that I won't be writing down the notes given, but not to worry, I will still remember them.
Journal writing works for some and not others. Maybe you could suggest that those who don't wish to write down observations could work on pieces of fiction, etc. And that comes to the next thing I would like to see in the class:
Too often students in such classes are made to do little exercises that illustrate a point, small short writings etc. I think of course it is important to do these things, but maybe have something longer on the go as well. For the last ten minutes of every class, the students get a time to just write what they want to write. Be it a novel, short story, song, whatever. I always hated writing classes that didn't let me write what I wanted to. It removed the fun from writing creatively, and for that reason I wound up being more creative at home than in class. You want to, above all things, instill a great sense of fun in such writing. And so many of these classes wind up taking away from it.