Gahhhhh! Nursing instructor here- Please don't flame me!
And sorry my post is long- I'm going to try to give you the rationales of why teachers do what they do.
And I'm not an old one either, I graduated from nursing school in the early part of the 2000's, and hated doing careplans then. Didn't really get the point until I was an RN and in grad school.
And I do not waste time during clinical going over them. The students need to care for their patients! The only time I will review a careplan is if I get the feeling during report that the students didn't know what the heck was going on with their pt, then I will take them aside and try to determine if they don't know what is going on because they didn't pre-plan well (which may result in going home) or if they had a weird/ difficult pt (which will not result in going home).
One of the main reasons schools use careplans (other than it being a nursing thing) is so students can learn the material. So when you become an RN you will be able to rattle off some E0's and interventions (along with knowing why you are doing them) in your head when you get that new admit.
And for the most part RN's do not use careplans a whole lot doing day to day work, but that is because they have already internalized the information and proven their knowledge to the state board and a college (which resulted in the form of a degree).
Formed care plans are a set and organized way for students to show me how much they know so I don't have to pimp them the entire time of clinical. I can leave them alone so they can do their work. My husband is an engineer, and during school he had to write a load of lab reports. He NEVER has to do this now, but he did it then to show the professor that he actually learned something and could advance in the course. Careplans are pretty much the same thing (to me anyway).
Here is what I expect (and why). I teach peds clinical, so some things are different. And for me, if a student copies a careplan straight out of a book, they are most likely going to get it wrong, because the books can't individualize care for a pt. All pt/families are different, so a care plan is individualized to the pt you are caring for.
I want my students to write every possible, actual or risk for dx, because I want them to look at their pt as a whole, see how one disease process can have an effect on many areas, and be able to recognize potential problems so they can intervene before it become actual- if possible.
Nursing dx: After the R/T I expect to see WHY or HOW ( such as pathologically- what is going on). For example, if it is an open appy who is on morphine. I don't want to see Constipation R/T morphine use. I want to see Constipation R/T decreased intestinal motility due to use of morphine for pain. I never want to see a medical dx, because it doesn't explain the patho. And the AEB should be physical assessment findings, labs, or pt statements that back up the use of the dx.
Why am so picky about this? Because I am eternally suprised that many nursing students are so poor in patho. How can you know what problems to expect if you don't know how and why the body is going to respond to certain diseases/meds? How are you going to explain a process you don't undertstant to a parent or patient? And I want to make sure you are doing good assessment techniques even when I am not around to watch.
Expected outcomes: I want these to be measurable and specific to the pt. I teach peds, and we get all shapes and sizes. So I want to make sure that the student knows what is normal (and what isn't) for each of the age groups we will take care of. I want it to be measurable so that we can have a black and white way to to determine if the goal was met. I started being more strict on this when I discovered that many students didn't know normal Pulse, Resp, B/P for the different age groups they were going to take care of, as well as what pain scale to use with what child. Or what to expect from which age groups.
Interventions/Rational: This is so I know that you know what you should be doing during clinical as well as a way for me to see what kind of knowledge you have as far as a child's growth and development. I once had a student write an intervention for cough and deep breathe for a newborn. Now, HOW are you going to do that?
Yes, I hate grading paperwork during my weekend "off." But I know that it does actually have a point and that it can provide a different type of instruction. Sometimes I feel like this

because I'm just not getting through. But usually I feel like this

because at some point it all clicks in their head. That is when they start to think like nurses, and I love it!
And my students must too because on ratemyprofessor, I have great positive comments. I love checking in there to see what my students write!
Ok, sorry to be so long, but this is the type of thing that gets my panties in a wad!
Don't flame me too hard!