Historically, bad Latin and uncritical reading of "authorities" based on incomplete or corrupt corpora, and then materialism in the natural sciences proved so powerful that the idea that substantial forms have any causal power was almost entirely abandoned.
The Aristotelian claim that substances possess irreducible forms that ground their identity, unity and directed activities still has not been decisively refuted by science. I think at the very least a naturalized account of form as causally efficacious organization is highly plausible, while the stronger scholastic ontology remains a live but unverified interpretation.
The stuff he says about Aristotle is legit. Some of the stuff he says regarding biology is obviously crankery, but actually not bad if taken as metaphor.