Here's the deal. First, you might have a different view of how "protected" you are as a resident in terms of the 80 hour week when you get there. Many places are not yet in compliance, and even those that are tend to be protecting you out of moonlighting money (as moonlighting time would have to fit into that 80 hour cap), and finding various home networking ways to still have you working from home after the 80 hours is up. So the "benefits of the reformers who came before" is probably overstated, except in the more oppressive fields.
Second, you keep saying med students and residents are at different phases of their training and should be treated differently. Guess what -- once you get into third year the whole point is to start the transition to being clinically, not didactically educated. Hate to break it to you, but second year ended, and you are now in the next phase of your education, which is meant to be closer to the resident phase than the classroom phase. You still have some didactics, I'm sure, but in general, that phase of your life, the one where you cush up to a book with no other expectations but to read, has ended. You are no longer classroom wonks, you are clerking. That means you will primarily learn on the wards. Trying to draw a line and say, med students learn by sitting and reading in protected time, while only being on the wards part of the time, when there's cool stuff to do, is trying to recreate medical education. Your protected time to study ends with second year. Trying to cling to that form of education beyond second year is what is "pedagogically unsound". You are now in the next phase of your education -- one where you learn by doing and seeing, and squeeze in reading where you can. Get used to it -- it's the model that will be with you for the rest of your career. And it starts in third year, not once you hit residency. And no, the expectation won't be the same as for residents, don't you worry. But the format will be, from here on out.
Third, the problem with real life is it doesn't play out like a nice tight story. There's a lot of scut. You don't get to say, if things are "rocking" I'm there, but otherwise I don't see the point. Because taking the bad with the good has always been part of the apprenticeship model. There will be days where there is nothing cool that a med student can participate in, where the learning value is nil. So too with residents (who are still there for training). If there's something you can help out with, even if it's scut, you do it. Because you are being evaluated at teamwork, and at working with people/patients/coworkers. Sure, there will be hours where you feel like you could learn more in a book. And there will be programs that take on med students and aren't particularly sure how to use them. But that isn't really a good argument for a universal, "protected time" for book study. It's only an argument that programs that take med students should figure out how best to integrate them. Pairing them up with residents usually helps -- you don't always see the glamorous stuff, but at least you see patients. But saying -- I'm not learning much here so give me protected book time is trying to go back to second year -- basically trying to climb back into the womb. Sorry but that phase of your education ended and you will see will actually not have been the most effective phase of your career training -- just very good foundation on which to actually learn. Push forward, and you will see.