Why doesn't our media get mad at China and call them racist for trying to blame America for the virus?

Because the media tried Russia, Russia , Russia and then Ukraine,  Ukraine , Ukraine and failed . So now they are trying China China China and that is failing too because they are insisting that it's racist to say the virus came from China where it did come from . Many Democrats are tired of the media making their heads spin with such nonsense and walking away .

Why doesn't the media ' get mad ' at China for unleashing so many of the worlds pandemics on the rest of the globe ?

Because most media outlets have massive investments in China and they dare not anger their Chinese Masters for fear of messing with their money. That and TDS that means that everything is actually President Trump's fault.

It not in the best interest of their agenda. 

Because it is NOT racism.
.
DEFINITION - racism is a belief (A PERSONAL BELIEF) in either the superiority, or inferiority, of one race compared to another. It therefore (by definition) CANNOT be a characteristic of an entire group, an organization, or of an inanimate object: Source: 1950's University Sociology Studies textbook.
For your further reference: https://www.adl.org/racism
http://www.columbia.edu/~lnp3/mydocs/Blaut/racism.htm
For your further reference: https://www.adl.org/racism
http://www.columbia.edu/~lnp3/mydocs/Blaut/racism.htm

It's time to stop thinking about things from a borderingly perspective and come together as a planet. The coronavirus is the fault of no person and no country. 

maybe they already got mad at them

China isnt blaming anyone for the virus.