Which, okay, I basically agree with. If students choose not to come to class, they suffer for it, and that's their own decision, and I really can and do flunk them with a clear conscience when their performance warrants it. I flunked calculus freshman year, and I deserved it -- I stopped coming to class partway through the semester, in part because the material had started confusing me, but mostly because I had a new boyfriend (my first) and early morning class and late night homework were just not priorities. So yes, students earn their F's, and that's not my fault as a teacher.
But that said, I can't help worrying about the ones who are falling behind, or who just stop coming, which usually means that they've gotten overwhelmed by my class or their other classes or their life. I also get frustrated when they do come but clearly haven't done the reading; not just because it makes my job harder trying to lead a discussion of a book they haven't read, but because I know it means they'll have a harder time writing their papers later and their grades will suffer. I get stressed on their behalf, and I even get angry sometimes. Which, you could argue, is way too much involvement for a college professor, but I'm not sure I can help it.
The woman I was talking to originally had been teaching for a long time -- maybe long enough that she'd just gotten exhausted. I can see that. But I find that I actually am more engaged with my students' struggles now, ten years in, than I was when I started. I care more every year, it seems. I don't think that's going to change, so I guess all I can do is try to manage that care, so I don't exhaust myself and drive them all crazy in the process. There are limits to how much effort I should go to, trying to help them save their grades.
But that said -- if my teacher freshman year had realized that I had suddenly stopped doing my calculus homework and taken five minutes to stop me and ask me what was up, that might have been enough to catch my attention back then, to shame me into going back to actually doing the work. Maybe I would have passed that class, and that F wouldn't still be grating on me, almost twenty years later. Sometimes, it just takes a few kind words to let the student know that someone cares about their grade, and their learning.
One of the studies I looked at noted that the greatest predictor of student success was the student feeling like someone (teacher, parent, etc.) actually cared how they did in the class. So okay, that part I have down. I care. Now I just have to convince them, without driving myself nuts.