With housing bubble and all, it seems that this is part of a long-term trend. Choosing 1975 as the hypothetical standard of where the ratio might return seems completely arbitrary.
Anecdotally, the standard advice I've always heard is that you should look for a house priced at around 3x your annual salary, and that you should be able to make a 20% down payment. If it's not possible to find a reasonable house which fits that, then there's a problem somewhere.