Quantum theory is widely accepted among the scientific community. It has been extensively tested and confirmed through numerous experiments and observations. The acceptance of quantum theory is virtually universal among physicists and other scientists working in fields related to quantum mechanics. While it is difficult to provide an exact percentage, it is safe to say that the overwhelming majority of scientists accept and embrace the principles and predictions of quantum theory.
It's worth noting that there may be debates and ongoing discussions about the interpretation and philosophical implications of quantum theory. However, these debates do not challenge the fundamental validity of the theory itself. Quantum theory has proven to be an extremely successful and accurate framework for understanding the behavior of particles at the microscopic level and has led to numerous technological advancements.