If freezing food kills bacteria, does it follow that frozen meat or defrosted meat is safe to eat?

The best answer to this question is what kills bacteria, and when bacteria multiply. The answer is that bacteria is killed in high temperature, or very low temperature and multiplies in the process of reheating or cooling down. The window for bacteria to feast and multiply is when food is left for a period of time in lower then 145F to higher then 45F or vice verse. To answer your question is yes and no. It is yes only if you eat raw product for example if you are making beef carpaccio or sushi then it is suggested to freeze the fresh meat or fresh fish before use. It is no because bacteria grow in the processes of food aging, food preparation, food handling, and cooling time. To my experience it is better to buy fresh product and then free zed.