Answer:
It prevents them from injecting bias into their experiments.
Step-by-step explanation:
For scientists, it is important to be open-minded because a scientist searches for answers and knowledge that remain unknown to date. So, if the scientist remain close-minded they will not able to explore the nature and won't be able to receive new ideas in their mind.
Science is a research and experimentation of nature. And to do the research on nature a clear mindset with clear observation is required which can only happen with open-mindedness.
If scientists are not open-minded then the possibilities are that they will be biased in their experiments.