Classic question: does knowing people in academic circle help?
The answer is definitely yes, not only for admissions but for everything in life.
Unfortunately, not everyone has access to people who could help in the admission process. That is something good I guess, it makes the process more objective. So, if you don’t know anyone personally and your recommenders are not well known, don’t panic. Your chances of getting admissions are high enough and anyhow there is not much you could do about it.
So, does that mean you should go out and write tons of mail to professors? I would suggest against it since the possibility of making a good reputation via mail to an extent that professor helps you in the admission process is infinitesimally small and the information that you would get from the professor, could easily be found on their personal website or school’s website. Another reason you should not contact professors is: while science doctoral students work with their advisor within months of joining in, business doctoral programs take a more independent path for students with at least one (normally two) years of course work. So, the professor might not know you for few years after you get admitted and this makes it even less likely that they would vouch for you prior to admissions.
One situation where you could write mail and it would be beneficial for you both would be to inquire to the professors, whom you are interested in working with if they are taking in students. This sometimes helps you drop few colleges from your list, in case they say no.
Just to emphasize, don’t worry if you don’t know people in the academic circle. There would be few people who will get into colleges because they had worked/ know someone. However, the majority of doctoral students get admitted each year with almost no prior knowledge about anyone in the campus.