That's definitely true in some countries, particularly the US, but Canada does a fairly good job of helping those at the bottom.  Unlike the US we have a strong social safety net so I don't think it is a problem in Canada, but certainly is in the US.  Although in the case of the US their tax system is quite progressive and top rates are fairly high, the problem is they are riddled with loopholes that allow the rich to pay well below the published rates.  Also a big problem there is cultural more than anything as it seems greed is celebrated more there and changing cultural attitudes is not that easy.