Poorer relative to what, though? I'm not going to run through the argument of "oh these days so-called poor people have Plasma TVs and stuff", but to some extent there is a point that this is a different kind of poverty from the blackest days of poverty in the past, such as most recently in the 1930s. As a whole, since then we have got markedly richer -- yes, with exceptions -- so if the poor in modern Britain are getting poorer then it is from a position of relative strength compared to the past.
At the very least it ought to be clear that far fewer people are in real, dire poverty than you would need for a "revolution" of the sort Hanauer or that other person was envisaging, and if the poor are taking a hit then it's a short-term one that bucks the trend of the previous several decades or so when people did as a whole get richer. If the same number of people stay in relative poverty that's due to redefinitions of the poverty line.
In absolute terms, the definition of "international poverty" is defined as an income of about $1 a day (it may have been revised upwards). By contrast, in 2006 before the Recession, one report in the UK spoke with abject horror about "5 million people... earning less than £6.67 an hour." It's a different and 'better' class of poverty that we have in this country, markedly, from most other places. In virtually every other metric you can think of there's the same sort of picture, of living standards improving as a whole, and the result is that there is just not enough anger, and not enough angry people, for large-scale revolution to be at all likely.
The closest we got was in the August Riots of 2011 -- but even then, if it started off due to anger it quickly became overtaken by simple opportunism as people saw the change to grab stuff free of charge. With signs that the economy is improving, that was probably the last chance for a Hanauer-esque revolution to have any real support for a generation or so, at least in this country.