Firsty, corporations do not exploit people, they pay the wage that people are willing to accept. Secondly the wage rate in regions is determined by the demand for such labour, and ultimately the supply of labour.
Immigration of low skilled workers decreases or keeps the current wage rate of such occupations stagnant. The London living wage has only come about because of excessive inflation/costs caused by huge flows of capital and rich folk buying land/property and high immigration. it's a political decision and has nothing to do with supply or demand of labour, however that has been the cause of it being brought about.
In regional terms, the higher the supply of labour as opposed to demand sets the wage rate, companies simply pay what people will take. People will take this lower wage(ie migrants or british people) because there's a substantial imbalance in the labour market, where the labour market increases in size, people have less options jobs wise and less opportunities for employment, so they are forced to accept the lower wage rate. The more people you have in a certain area, the cheaper production/labour costs are as there's more people to do the job. Look at countries with high populations such as China, China may be becoming very wealthy, but the people aren't as wealthy to represent that, hence why children never see their parent's as they move to cities to work all the time.
I do dislike the attitude of the middle and upper classes in this country that unemployed people are lazy, most unemployed people would like to have a job and be able to support their families respectively. And the whole attitude of a non English person shouldn't be able to take your job, because even skilled jobs especially in the building trade you can get by on knowing sod all English.
I'm not going to even go into the whole capitalism vs socialism thing as capitalism is the best economical system in the world. Remember Karl marx was funded and basically lived of his friend Engles whose father was a factory owner..... Essentially you could argue Marx lived of the "exploitation" of others.
As for it being a lack of education, if everyone was more educated you would find smart people being forced to accept lower/less skilled jobs not suited to their potential and would drive down wages of the middle/middle upper class. The richest people in this country will still become richer, inequality would only close between middle and lower class. Look at the earnings of the past 30 years of each percentile, the poorest are no better off than they were 30 years ago. A combination of high migration leading to stagnant and higher competition for jobs has caused this, you don't have the middle/middle upperclass or upper class worrying about jobs, because quite simply, the supply of labour for their jobs vs demand hasn't increased substantially. Not all people are intelligent, that's partially a good thing if you are intelligent as it means less people can do your job and as such you can demand a higher pay packet. I wish people would honestly have more patriotism in this country for the sake of British people that aren't born intelligent/able bodied.
Immigrants are the primary cause of these labour market shocks supply wise, the government is to blame however, but the government has no interest in reducing immigration, even if it means the poorest britains will become better off, or the middle class becoming better off because it reduces labour costs and as such costs to running business and government expenditure. Immigration is simply a massive supply side policy. It also helps increase demand for housing, which essentially makes people capital worth more, especially the rich and powerful, they have no interest in the British people but only an interest in their own wealth. Labour won't help the poorest either, since they're a huge fan of mass immigration because it ultimately means more poor people to vote for them, even if they helped cause the housing crises, they can use it as an election promise, the Tories won't either, simply because it keeps costs down for most of their companies that pay them.