It's definitely a hard company to get on with. I know a lot of people that have applied numerous times and unfortunately didn't meet the criteria that they were looking for.
This isn't necessarily a con, more of a piece of advice that some people don't like to hear... Your education with not solely suffice for a given position that you're applying for. You must have the experience or some sort of past experience that relates to the position. It's not that Insperity doesn't appreciate the education you worked hard for, they just want to make sure that you can also demonstrate the work that goes along with the degree