Here is the first line of the comment you are responding to:
> You can't eliminate inequality but you can reduce it. We can't eliminate disease but there is still medicine.
That was the important part. Making things better is desirable even if you can't make them perfect.
Inequality has indeed grown steadily. This is not because of FDR's programs, though, but because of measures taken since and other events: reducing marginal tax rates, reducing inheritance taxes, the weakening of the labor movement, globalization, and so forth. Also, incidentally, by asserting this you are contradicting your own previous assertion that nothing anyone has ever done has had an effect on inequality.