It sounds like it has the potential to be.... I know if someones daddy was a congressman it would certainly give him the edge over another guy.
Again, you're not understanding how the system works. There's a chance of this, but it's oh so ever small and the process is fairly transparent.
Each congressional member only gets 5 slots for each academy. The Naval Academy alone has 12,000 applicants a year. They only take ~1200 (or less). Each congressional member is usually going to have 4 slots filled (one slot for each Plebe, Youngster, Junior, Firstie) and then one slot for an applicant. Some will have an extra slot because someone at the academy quit. But in many districts, there's lots of applicants.
The "committee" is not some sub-committe on Academy selection in Washinton DC. It's a board of a couple of people and some admin support. Just like what happens in the military when someone goes to a board. They interview and make recommendations. It's actually very apolitical (most of the time).