Final answer:
Criticism of Wasson's Soma theory often centers on the absence of concrete archaeological evidence and insufficient botanical evidence to confirm the identification of Soma.
Step-by-step explanation:
One common form of pushback or criticism against Wasson's Soma theory is a lack of archaeological evidence supporting the theory. Critics argue that without concrete archaeological finds to back up the theory, it's difficult to substantiate Wasson's claims about the use and significance of Soma. Additionally, despite Soma being mentioned in ancient texts, identifying Soma with any specific botanical substance has proven to be challenging due to insufficient botanical evidence. Contradictions with historical timelines could also be a source of critique, particularly if Wasson's theory does not align with established understandings of historical events or cultural practices.