Dell Computer Corporation Dell Sold faulty laptop , I googled to find that ALOT of other ppl had the same problem a month after warranty expired. Round Rock, Texas

The thing is this, I know laptops need to breathe, I always kept my laptop on a hard flat surface, but when it burned my leg, I had already shut the laptop down. I did some house cleaning and even watched some tv. My husband and I were going to my friends house for dinner and she wanted me to bring my laptop to use, so I took it off the table and set it in my lap to put into my carrying case and even after it sat that long after shutting it down, it still burned my leg. That just shows how hot they can get. So, it was at no fault of my own I can assure you. The M5030 model has had a lot of negative reports about the mother boards, just too bad for me that I didn't know this until it was too late. Google Dell M5030 Laptop and you can see for yourself the trouble a lot of ppl are having with the 7 beep code. Some of the complaints are even on the Dell website for that model. 

You might have unknowingly provided the answer to why your laptop went bad. "They said the mother board could be replaced, but there was no guarantee
it would last a year because that particular model laptop was known to over heat, which I know for a fact because I have the scars on my knee to prove it! "
As a Computer Technician of over 20 years, one of the first things I would ask a customer was "Did you hold your laptop in your lap at all times"?  There are no laptops that I know of that can be used exclusively in your lap. Material in your clothes can and WILL block the vents that have been placed on the unit in various places, thus causing the unit to overheat. I would probably tell you that a year of using the laptop this way(1 year, usual warranty period unless extended warranty has been purchased) could indeed cause the unit to "go bad".
Usually it is a good idea to use a laptop on a desk, cooling pad, or some other smooth surface that will allow air to circulate as it should.
I'm not saying that you misused the unit, but overheating it on a regular basis will indeed cause it to quit working.

"How can they not know that a majority of that particular model wasn't faulty"

Read what you wrote. You are stating that a majority of them were not faulty.

You have no idea how many units of that model were sold; therefore, you have no idea what percentage were faulty.