What are your opinions on DiEM25 and its founder Yanis Varoufakis?

Having read some of his works and seen a few talks and interviews, he explains very well why capitalism doesn't work, kills our planet, people, and the democracy it's said to promote as the capitalists believe (or want us to believe anyway). His ideas are not purely Marxist, though they are inspired by Marxism among other theorists.

Leaving details aside, he supports full state ownership of banks and a system where each company's shares are evenly split among the workers who have the right to vote or abstain on any decision the company (the collection of all the workers) makes, even when it comes to hiring people and financial managing. Those shares are not tradable at all, they serve to resemble your partial ownership of the company and right to vote in its decisions, and it disappears after you leave the company.

There is more depth to it and you can also read the manifesto in the website.

Is this a theory that could work out and sustain itself, or is it another fence-sitting opportunist theory? Personally I think there's creativity in it, Varoufakis has a very clear understanding of economics so he gives a pretty unique approach to things, but it also kinda reeks of a capitalist system waiting to emerge.