I'm really surprised that the people teaching at Harvard don't seem to be putting forth any effort to make assignments that are at least somewhat difficult to c

I'm really surprised that the people teaching at Harvard don't seem to be putting forth any effort to make assignments that are at least somewhat difficult to cheat on. I'm only a grad student at a Big Ten school but I always try to make my assignments require something that they can't just copy down from someone else even if it is just randomized questions. Obviously this is easier in some disciplines than others but even when I was an undergrad back in the early 90s I took an intro-level Physics course where every student's test was randomly generated from a bank of questions (admittedly it wasn't very good. One test I remember getting the same question 3 times!).