That is incorrect. Stages of grief do not only apply to terminal conditions where acceptance is fatalistic.

Say you suffer the loss of a loved one. Accepting that they are gone holds within itself the key to continue your live. Acceptance, plain and simple, is a necessity to deal with reality.

Similarly the acceptance that the capitalist system is inherently "broken" enables us to figure out how to deal with that reality, how to overcome its contradictions.

Denying that many of humanities problems are rooted in capitalism does not. The comparison is valid