It is hard to give realistic macroscopic analogies... that is the thing with the microscopic and nanoscopic world - the behaviour is often not as one would expect from macroscopic world experience.
The best one I can think of on the bonding on the surface is superglue on your fingers. What happens when you rip your fingers apart? You rip the skin off at the same time. I realise that this is a totally different scenario but fundamentally you are applying a force larger than the shear strength of the system and you are causing a whole load of damage to the underlying area. Had you been using PVA glue, the glue (or top coating by analogy) would have been ripped apart whilst the underlying would have been OK.
For background, I am a chemical manufacturer, I formulate new products like most people eat snacks, my initial education and doctoral studies were in atomic and molecular physics and I have also studied and published for a time in silicon and semiconductor surface modification. Not to say I cannot get it wrong... but if you are interested in learning, don't dismiss my thoughts without taking the time to reason through and do a bit of reading on the topic.
I'll shut up now!
