"5000 hours of instructing aint 5000hrs, it's 1hr 5000 times".
You bet! Although can be very rewarding still.
No the intent is to let students know that they only need to forget the landing gear once in their career and it's wheels up. In other words, their attitude towards checks needs to be 100%, not 99%.
I understand the multitude of contributing factors that goes into landing gear up including missing warnings, ATC R/T, checks, CRM, company pressures, fatigue, etc. Obviously nobody wants to land wheels up and it's not as simple as "You're **** if you do" (we all make mistakes).
The student needs to be made aware of their link in the sequence of events leading to a gear up and be as disciplined as possible to maximise their chances of saving themselves when all the other holes in the cheese line up one day.