Getting a visitors visa is a lottery. Yes you need the documentation, money, a secure job, etc. But even after that the visa is not assured. The request can be rejected for any reason whatsoever. I know of a person whose both children are in Canada doing not so great jobs. The person got a visitor visa in the first attempt and the person does not have any family ties in India. What family ties can you have when your children are here. You have an extended family but than in India everyone does. So my point is the visa could have been rejected as " no sufficient family ties in India".