The trend is going on for decades now. The rise of the finance sector is IMHO the main reason.
In the finance sector, multitudes more money is flowing today, than in the real economy with products and services. Big money is going, where the most interest is been made ... but the interest must come from somewhere. To think, that it just appears somehow and everybody is getting richer, is just wishful thinking. Finally, some day, somebody will have to work for it or somebody will loose something (e.g. land that is sold to investors, that use it to generate even more money).
So, more and more interest is made by investments, money lending or even speculations. Who are the losers? The working people, that just have not enough money to invest and use their working power or their brains to get the money for living.
Globalization is helping this trend. Money can just go where it is cheapest, instead fighting fights with worker organizations. In many countries, people are so desperate, that they sell their work for a prize, they merely can survive on.
Trend is going on. Money seeks better places to invest, more land to grab, more patents, more, more, more -- and for those that have not got money already, the possibilities to earn money or to get better of are vanishing, since more and more land is owned, more "intellectual property", more lobbyist, which say, how the laws shall be that shape our future. Also more trade treaties, like TPP, TTIP and the others, which create better conditions to invest and to make profits for corporations ... which are owned by big money.