Among other consequences,
-If a lack of free will is accepted, it makes certain emotions like anger obsolete. What is the purpose of things like vengeance or anger towards an individual if it can't be said that individuals have anything we'd call free will? Who, exactly, would I ever be angry towards? This has all sorts of applications in legal systems, too.
-If a lack of free will is accepted, it implies a person should be humble. Suppose I succeed at something- can I take credit? What "self" am I identifying the credit towards, if it cannot be said that I have anything I'd call free will?
-In addition to some positive things, if a lack of free will is accepted, it can conceivably affect a person's level of motivation. Feeling in control of things seems to be a big part of motivation, personal development, relationships, engagement with activities, responsibility, etc.