Once a legal adult, one is free to take all financial decisions. Parents can be a valuable contributor as they have experience with them and can guide one taking the right decision. I mean it is always good to discuss with people who have idea about financial stuff and have their own personal experience..A healthy discussion and exchange of ideas is always a good thing. But then one should not force something or despise off every idea of others. I am not sure how old is your friend and whether he depends on his parents for any sort of financial assistance. If their money is involved, they can be dictating the terms.