Except that rich people have an inordinate amount of influence over public policy. Therefore, the policies that work to make the rich richer and the poor poorer are the responsibility of the rich. They're stacking the deck in their own favor.
Let's just look at the problem outlined in the OP. Let me try to connect the dots for you, since you seem willfully contrary on this.
1. Homeless person poops in Safeway.
2. Why is this person homeless? Because he can't afford to buy/rent housing.
3. Why can't he afford to buy/rent housing? Because it's too expensive or he doesn't make enough money (or a combination of the two).
4a. Why is housing too expensive? Because a rich person decided (all on their own) to set the price too high and is clearly demanding more money than he/she actually deserves.
4b. Why does the individual not make enough money? Because a rich person decided that they should be paid less and not get enough to live a decent life.
So, it seems quite obvious, self-evident, and logical to me. The situation is as it is because of the questionable choices made by rich people, ostensibly due to blind greed and nothing else. The only remedy is intervention from above, either in the form of higher taxes on the rich, wage/price/rent controls, or similar measures to equalize society and level the playing field.
When Reagan took office, his theory was that, by lowering taxes on the rich and deregulating the marketplace, it would encourage the rich to spend more, invest more - with the idea that the benefit would "trickle down" to the rest of society. That didn't happen. The expectation was that, in an unfettered, deregulated market with low taxes, the wealthy would have greater freedom of choice, with the assumption that they would make the right choice which would bring about the greatest benefit to America as a whole. At least, that's what they promised, and that's why a lot of people voted for him.
Now, nearly 40 years later, we see that just the opposite has happened. Even though Reagan believed the wealthy would make the right choices if he gave them freedom to do so, it's clear that they did not. They pushed for more outsourcing and created the Rust Belt. They strongly opposed labor unions (which is hypocritical from those who claim to support a free, deregulated, laissez-faire society). They cut social programs which left a lot of people out in the cold. Meanwhile, they continued to support interventionist warmongering, fiscally irresponsible borrow-and-spend policies, and an insurmountable trade deficit. The infrastructure is collapsing, our once-booming industry is dead, America's credit rating is sinking, and our influence and prestige around the world has also decreased to a measurable degree.
Who do you think is responsible for this? The poor? The working class? They don't set policy or influence society.