That is only partly true.
If the court determines something is unconstitutional, like their claim on gay marriage, the legislature is blocked from going forward with it.
If the decision is based on how a particular is written, the legislature can change how it’s written and fix it.
“If the court determines something is unconstitutional, like their claim on gay marriage, the legislature is blocked from going forward with it.”
According to whom? The court?
Courts cannot write law. Only legislatures can write law. Look it up.