I mean yeah, at the end of the day increasing inequality always leads to unrest and revolt, sure, that's undeniable. Happened numerous times in the past, it is happening in the EU right now, and surely will happen in the future too. But I don't believe this can be solved like Marx imagined, even with psychology and neuropsychology added to the mix.
IMHO a strict, exhaustive, well thought-out, rule-abiding system with rock-solid breaks and balances is necessary at a minimum, not unlike how Solon and Cleisthenes reformed the entire system in ancient Athens. Demokratia was very different to today's democracy, it was an air-tight system that covered all corners without any loopholes. For example, voting was considered a work, therefore voters got paid (which made vote-buying futile, making the whole process corruption-free), and thanks to public lottery it was impossible to bribe or persuade the judges, as nobody knew in advance who they will be. It was a system that aimed for rights must not be influenced by wealth and status (which is the total opposite of today's democracies, where only the wealthy can run for presidency and have a say in lawmaking, not the common people).
IMHO fighting inequality can't be based solely on some ideology (maybe with psychology on top), but must be a multi-disclipinary effort covering all aspects of society like in demokratia. I'm not sure if even this could succeed (Greeks failed after all), but I'm sure without it will just reproduce the vicious cycle that Marx spoke of.
Oh, sorry, we have derailed the topic a bit, hope other readers don't mind.