This is truly the case where you cannot apply this rule to all schools. Yes, there are certain programs that have definitely decided on a younger class profile so candidates who are older than 30 years old are pretty much excluded from the process simply based on their age and experience levels. However, most top schools are not following the lead of others and they are accepting older, more experienced students. I encourage you to take your research to the next level and see the class profiles of the schools you are interested in as well as speak to students (do not speak to admissions as they will tell you that everybody is treated the same - as they have to -- as they cannot discriminate based on age). The same is true for the under 24 group.
I would also recommend that before you get started that you sign up for a free candidacy evaluation with Manhattan Review. This will provide you with a wealth of information on the admissions process as well as give you specific feedback on your candidacy.