If you have the desire and passion towards a subject you would want to gain the knowledge about it but if you only have the knowledge about it without passion you would regret having the knowledge about it. Passion and desire takes out the best in you, recent studies claimed that having the passion and desire is just as important. If you have a business and you're passionate about it you would want it to become the best business in the business field.
I believe that knowledge and the desire to learn is more important than the focus on success. However, without any real objective life purpose, either could be more important to any individual. I do try to work towards success, so I tied that to my search for knowledge and will head to a physics major.
I do agree both are required to get success in life, but effort is more important. For example- to make a successful program which can run, we need to do lots of efforts, knowledge is same for us, this is the effort which makes people out of the box and successful.