Are students' college choices irrational ?

This morning's papers report big falls in the points requirements for construction related degrees like architecture. No surprise there. But hang on a minute: it should have been obvious for some time that the property market was crashing.More importantly the current state of the market should have little or nothing to do with career choice. For a start they would not be graduating for 4 years by which stage the market will probably be very different - think it was different it was 4 years ago. Anyway the human capital model assumes people maximize the present value of lifetime earnings. So is it myopia, some other form of irrationality, a very high discount rate or something else ? ( oh no, is it hyperbolick discounting?)