The distribution of bitcoins is not relevant to the distribution of wealth.
Bitcoins are not the same as wealth. Do you think it is unfair that only 0.5% of the people in the world own 100% of the Albanian leks? Think of all those unfortunate Americans that own no leks at all.
The distribution of bitcoins is insignificant compared to the distribution of wealth.
If you distributed all 21 million bitcoins evenly to every person on the planet, then each person would have about 3 mBTC, or about $1 USD worth. Do you think giving $1 to each person in the world will make any difference at all to anyone?
Yes but if BitCoin was to get as big as some people want then they would be a reflection of wealth - period.