I would not blame the software in so much as it did was it was told to do, crash the plane by driving it down as a result of a perceived fault of a wrong angle of attack. The software performed "as designed"
The report to Congress in late 2020 is 234 pages long with lots of blame to go around.
Pressures to update the 737’s design swiftly and inexpensively
Faulty assumptions about the design and performance of pilots
What the report called a “culture of concealment” by Boeing
Inherent conflicts of interest in the system that deputizes Boeing employees to act on behalf of the government
The company’s sway over top FAA managers