Vostro 7620 LCD hinge cracked by itself while sitting on my desktop, design flaw/poor manufacturing

My Vostro 7620 is about 22 months old, sits in my office on the desk except for I believe 4 times taken outside the home.  I just noticed a couple of weeks ago that the back left hinge has cracked.  I had purchased the extended warranty but this was useless as Dell says this is normal wear and tear and what should be expected as almost 2 years old.  WHAT, is that the lifespan of their laptops 2 years?  This laptop sits on the desk screen open and maybe the screen has been closed down 200 times at most, so this is the life span, 200 times you can open your laptop and after that sorry, normal wear and tear.  I believe this is a manufacturing default / product design issue.  The design is such as they say that the LCD panel works as a base for the laptop and pushes the bottom of the laptop up slightly to aide with cooling and it needs it causer it runs hot!.  Dell will not admit this is a product problem even though the internet if full of clients with the exact same crack in the hinge problem.  If I can't get satisfaction then no more Dell products for me as it wasn't cheap and they don't stand behind the product at all.