What is the context for the man or woman in a divorce, enacted because she burned his meal, for example (Hillel)?  The Shammai position makes even less sense because divorce is only enacted upon a spouse's infidelity - an act already punishable by death which ends the marriage, anyway.  That's the context, on a hornbook.  What Jesus said (or at least the explicit message that has been captured of what he said) is quite simple and only needs "guidance" in the debate if one seeks to guide another party away from the clear message.