Sure, it is for their own good to do it. But frankly, college students are too immature to realize it, and even the ones who do realize it have to fight with very strong procrastination motivators. You can't expect them to deliver this kind of stuff based on internal motivation only, they don't have it.
If it is your goal to get them to pass, you have to give them external motivation here. The usual method is to make homework obligatory.
The idea behind it is simple. Anybody who gets less than 80% of the possible points on homework assignments is not allowed to take the final. If you want to be mild, or the homework is very tough, set a lower target in percent. If you want to include very interesting but very hard problems in the homework, mark them as "optional" and don't make them count towards the required points.
This also has the advantage (from a grader's perspective) that students who cannot muster the dilligence to achieve 80% correctness when working in a relaxed environment with little time pressure and with the help of their friends, their textbooks and the Internet, will not be present at the real written exam where they are only going to waste your time. But it also makes them learn for the homework, spaced over the semester, so the students who have the intelligence to beat the exam but procrastinate until the last two days to learn without deadlines are actually learning well and get their grade based on solid knowledge, instead of passing on bulimia learning or plainly failing.
You can alternatively declare a number of homework sheets which needs to be turned in. E.g. if there are 12 homework assignments for the semester, you can say that they need to turn in at least 10 to be allowed to take the exam. But this is more problematic - what do you do with students who turn in an empty sheet? The percentage system works, I have seen it employed by many departments at two different universities. I have been exposed to it on both sides, as a student and as a teaching assistant/grader. It is well accepted by students and staff alike, it is perceived as fair, and it works.
You will probably have some problems championing it, both from students and faculty, but once you get it established, everybody benefits.