some of us don't live the lifestyle you describe.
bill gates is a product of his society. he could not be where he is without his education, his birth, and so many other things. i'm not suggesting he owes anyone anything. but he and all other excessively rich people have two problems. first. they continuously lobby congress to eliminate their taxes, so they don't even pay their fair share to running our nation. second, our activities have made them their fortunes. our demands and (in most cases) the labor of people in underdeveloped nations being paid less than a living wage, not to mention the people here making less than a living wage. they have used millions of people to get where they are. they do owe those people something. further, if we all die of global warming (thanks to those hummer manufacturers and all the rich assholes who drive them, not to mention our dear dictator and his friends at haliburton) then we can't buy their blessed, wonderous bullshit that makes our lives oh so much better. they have a responsibility to humanity just like the rest of us. my responsibility is to drive less, walk more, throw (more stuff now because of the new waste management power thingummy) less away, spay or neuter my pets, take advantage of my education, be a mentor, keep my cpr certification up, and give to charity. bill gates has a bigger responsibility because of his greater resources. we all owe each other. we have the responsibility to care for each other and to prevent our world from killing us. if bill gates doesn't fight aids, it will kill his children and his line will fail. if bush doesn't fight global warming, the polar ice caps will melt within 50 years and our world will be entirely different and we might all die.
you say they have the right to keep every penny of their hard earned money. i say that every one of us owes our fellow man concern.
not to mention that most of their hard earned money came from not paying their janitors well enough and not paying their manufacturers enough.