Well, let's keep something in mind.
Without government and public support, no one gets rich. The government provides roads, police, fire brigades, and the infrastructure for practically everything, including your ability to have an internet connection.
Withough people to either hire you or buy your goods or services, you get nowhere. Without the people working under you, taking care of the menial stuff, you get nowhere.
Every rich person owes their success in equal parts both to their own hard work, AND to the society in which they live.
Do we owe anything to people who can't support themselves? The operative word here is "can't." And yes, we do.
Let's keep in mind high IQ is more prevalent in those with mental illness. Let's keep in mind that Stephen Hawking is completely paralysed. Let's keep in mind that even people with severe retardation can be savants.
There are many different metrics upon which to measure human value. Ability to support oneself is not the only one. Great works of art, science, and mathematics have been contributed by people who couldn't support themselves. We wouldn't be where we are as a society without them.
Even if this person is not a genius or a great contributer, that doesn't negate their right to life. They were brought into this world without consent, and if they truly can't support themselves there is no one to blame. This doesn't give us the right to kill them. That isn't what civilised societies do. It also doesn't mean they're a drain on the system. What if they spend their time helping a charity to whatever extent they can, or tutoring kids in piano? Unable to work doesn't mean unable to take part - just that they can't do that on the same schedule or to the same degree as able people can.
Now, with all that said.
Do I think we should tax the rich more? Yes. Do I think we should tax them more than 50% of their income? No.
We're still a capitalist country, and they are still entitled to at least the majority of what they make. Since they have more, and they also rely on society to maintain their status more, they should pay more than people who aren't rich. But I don't believe in "equalizing" people. People are not equal. Sad, but true. Some people are smarter, or more hard-working, or more able than others.
Balance in all things, basically.