We never question if a son or daughter of a doctor chooses to be a doctor. The choice of a profession is the right of a person. Yes, I agree that in film industry and politics, the trend is more. Or maybe, it is more noticeable because these are popular fields and quite covered by media. I also do agree that the struggle to get launched in films or politics is less if you have a family who is in to that field already. But it holds true for other professions too. If your father is an artist, you will inherit a well established studio without any effort. Similarly, you get well established nursing home from your doctor parents for no effort.
But to succeed further, you need to have your own talent. We have seen sons of superstars getting rejected by audiences. And so is the case in other professions. So your success will depend on your talent, grit, hard work and of course your destiny.