The difference between opinions in this thread is interesting.
I think it's mainly because some see a punishment as revenge and others as correction.
But, as user publius_0xf3 is showing, revenge does not work. The victims don't get their money back.
If this sentence is used as correction I also think it does not work. Would such a correction really take 25 years? His life is over. I don't see how such a long time is helpful to him, to his victims and to society.