One must be smart, but there's a level of trust given to the lenders to lend responsibly. We're always told to aspire for bigger and better, if that looks within reach because the banks are willing to lend the sorts of money required to get the bigger and better house then it becomes normal.
There will always be the assumption that if the banks are willing to lend such quantities then the banks can afford it, and they've done the relevant financial analysis of the applicant to make sure they can afford it too.
I do agree there should be a level of personal responsibility with all this, but the banks shouldn't have been lending in the way they were in the first place.
EDITED: 8 Dec 2016 12:32 by ANT_THOMAS