Why would my doctor not want to have a computer system that can do all of this?

One reason is cost -- cost which doctors perceive as excessive for something that does not provide much real world benefit for patients or doctors.  The EHR requirement was the brainchild of bureaucrats and politicians, not something that resulted from a groundswell of demand by patients or doctors.  These systems are expensive, running about $60,000 per doctor just for the initial hardware and software purchase.  The maintenance costs are easily $1200 to $1400 per month.  As the Federal government demands that the EHR software have more features to maintain certification, the costs increase.  The Economic Recovery Act could easily be considered the Software Vendor's Relief Act of 2009.   Although the Federal government offers a partial subsidy to physicians who adopt such systems early, the subsidies are small compared to the total implementation, updating, and maintenance costs.