Why DSLR?

I am really wondered thinking why people waste a lot of money buying DSLRs while they can use small P&S cameras.  No one can easily distinguish the image quality between the photos of DSLR and P&S.  If you look at the photos on your computer screen, both look like same, right?  Why don't you use the money for some other useful purposes?  I use a Sony S-750 P&S for the last 5 years and has no problem with it.  Why carry a DSLR and a lot of lenses and other accessories with it unnecessary.  I think all those who buy DSLRs except the professional photographers (who makes money with their photos) are fools spending a vast amount of money on their camera systems, while they can buy some simple P&S and enjoy the life.  What are your views on this?  Everybody is welcome to criticize and comment.  Thank you.