Why exam topper students in india are usually of parents holding a government job

Disciplined environment induced due to their office environment and as well the financial stability and security are the key factors driving their kids to continue education without any other insecure feeling.
  But in the case of rich families why it is not that prominent situation ?
  I say it is the discipline in life that is making a difference.

P.S: Here the word  discipline is understood in it's usual sense not as in 'bommarillu' sense.