Gentlemen, my post was merely a forum for my ranting. I don't claim to be perfect, nor do I expect it from anyone else.
There were probably reasons unknown to me that would explain that crew's actions. However, the fact that every other flight crew arriving here practically defines politeness and professionalism makes events like this stick out. It IS the norm to acknowledge a take-off clearance. It IS the norm to remain on frequency until advised...etc.
There probably is an explanation for everything. We've all had bad days. I guess the whole point of this thread is to learn from this fellow's bad day and try to prevent it ourselves.
Cheers