Business development and personal development go hand-in-hand. Without personal development there is no business development.
Doing work that is connected to your passion is like having an electrical cord plugged into the outlet. Without doing work that you are passionate about you can become disconnected from the larger circuit that exists by being connected to the outlet. Being 'plugged in' to your passion increases energy, motivation, positivity, satisfaction, happiness and success. You cannot create these outcomes unless you are 'plugged in'.
Employment, whether self-employment or within an organization, must connect you (and your electrical cord) to the outlet (aka your passion). Your passion can refer to your skills, abilities, talents, expertise, knowledge, experience. By being connected to your passion you feel a sense of purpose in the work that you do. In this state you are constantly innovating and creating the best of what you have to offer and you are continually learning about yourself and the product or service that you are providing.
An organization has to create the right environment for this to occur. This stems from the top of the organization down. In order to create this type of environment people (the 'leaders') have to stay connected to the people that they oversee and this must trickle down to each and every person within the organization.
The reason why this is so important is that people are the source of the business. They are the source of the products, of the services, of the innovation, of the teamwork, and of the connectedness that each feels toward each other and the organization. If you do not take care of the people you will not have a sustainable business in the long term because those people you do not take care of will not be taking care of the clients/people that they serve.
People first. If you do not get that right nothing else matters.