If there is no free will, on what grounds can we still praise or blame one another?

Discussing the premise of the free will question would get too long, so let me speak under the condition of "if there is no free will." I don't think the act of blaming has a valid basis. In the end, I think we would choose the attitude of blame because, given the limited resources we have for understanding the other person's perspective, we fail to understand and empathize with that perspective.

Still, praise has the positive effect of making both people feel good, so maybe what's good is just good, after all.