I totally agree with the OP but must also point out that these great philosophers (including Karl) didn't have the industrial revolution and the great wealth needed to achieve it's fledgling goals. To say that the wealth distribution now should be anywhere near five to one is not realistic. In a world where the division is probably closer to a million to one, in some cases, it is a hard sell to convince anyone with an acumulated wealth that there should be more taxes beiing paid by the rich than the poor.
Not to mention, who's going to impliment anything like this? Not our Government, thats for sure. Rich men, with their best interests at heart, run this country.
Gandhi's quote said it best:
"There is enough wealth to meet everyone's need, but not everyone's greed."

I think the first step is doing away with lobbiests, once and for all.
It should then be made law that no one that makes over $150,000 can run for office. Break up both parties and only allow independents. Vote first at the local level, then the state and then at the national level. National candidates should be allowed only so much air time each, with no mudslinging. The air time should be donated by the media. The actual jobs, in government, shouldn't pay huge sums of money. We need honest elected officials that will look out for the people, and our world, without figuring in their stocks first.