In the daily life of an average person, biology may be of little importance for them. However, it is important to note that the majority (if not all) knowledge on life was derived from biology. Other biological applications such as medicine (in conjunction with chemistry) also play a major role in prolonging the survival of human life in general. As such, I conclude that biology is indeed really that important in "real life", from the perspective of humanity as the stakeholder in this question.
If you want to be shopkeeper, then probably not, no. However, if you want to be a surgeon or doctor, or work in the medical field in general, biology is very important. You need to know how the human body works in order to work in those fields. Would you want a surgeon who got a D in biology working on your body?