Due to this design, ease of use and the overall egonomic benifits, how come other types of guns do not have a trigger like the 1911?  I know certain manufactures such as Sigs P-210 have a similar design, but it seems with todays technology a DA/SA handgun could be disgned with this style of trigger.  Any thoughts?

Unfortunately, the lockwork required with a DA/SA trigger does not allow a trigger with the characteristics of a 1911.  By the nature of the two functions in the trigger, there will be more takeup, and more reset.  A gun could probably be designed to have a first round DA pull with an entirely separate lockwork for SA, but it would be overly complex, bulky, and expensive.  The closest thing to what you describe already exists in the Para Ordnance LDA.