Is income inequality preventable? Should we prevent it?

Is Income Equality preventable?
At a conference in Chicago, an economist said that Income Equality can not be helped. It is a result of "skill premium" and corporations can not prevent this. Income Equality is permanent  Income Equality is often presented as the percentage of income to the percent of population. The rich stay rich, and the poor stay poor.
Should we prevent it?
We should prevent it but it is permanent. We are losing the middle class because of this. There is a growing gap in equality. People think that the wide spread between the "rich" and the "poor" is the primary problem for our economy. We could prevent an income gap by paying men and women the same wages. We can also prevent it by taxes, strengthening unions, and strengthening social safety nets.