in praise of not praising indiscriminately

I had posted earlier about praising children excessively. Here's some research on this.
It does not talk about the quantum of praise, but on what you praise. I totally agree that praise should be for the genuine effort made by and the sincerity of the child rather than on the outcome.
In life, outcome is not always proportional to effort and diligence. A child must grow up to value herself highly if she has done her best, no matter what the outcome.
However, self worth is quite ephemeral. I do not think it is fair to put all the responsibilty on parents. My childhood was peppered with stories of boys who studied under the street light and suffered neglect but rose to be great men. These boys had no praise, some of them had to live on charity....each day of the week, they would be fed in different households. No one told them they were great. Self worth is a much less cause-effect phenomenon and perhaps comes from something within us.