Accepting determinism and the insuing dissolution of free will is often feared as something that would lead to loss of will and fatalism. Gary Drescher and Eliezer spend considerable effort explaining this as a fallacy.
The one thing I don't remember mentioned is the opposite effect (but maybe I missed it) - if you experienced a failure to accomplish something, the free will explanation is likely to make you stop investigating the root cause, leaving it as a mystery. Once you accept determinism you know that a failure is determined by your mental algorithms, and should be much more motivated to push the investigation further, making yourself stronger.
The Stoics and Epicureans had very similar ideas (materialism, avoiding pain by understanding consequences), but the Stoics were waaaay more deterministic, and against free will.
They both influenced Roman politicians, but where Epicureans had a habit of retreating, many Stoics actually got things done.