At least he’s not a Leninist or anarchist insurrectionist, not what Neil Kinnock once called a “toy town revolutionary”. Workers here are not going to go along with that sort of thing.
Yes, apart from seeming to be a good trade union negotiator, politically he is a reformist but a rather timid one if what he wants to do is merely redistribute wealth from the rich to the workers. That was what the Labour Party used to say what they would do, but it’s a losing battle as the tendency under capitalism is for the rich to get richer, with the result than any redistribution away from them that might be achieved is eventually overcome by what capitalism is all about — the accumulation of capital (Picketty produced figures to show that, even if he imagined that it could be reversed). And anyway it presumes the continued existence of a class of rich people.
Socialists of course don’t advocate a redistribution of wealth within capitalism. What we stand for is the common ownership and democratic control of the means of wealth-production, currently monopolised by the ruling owning class. We want these taken away from them and vested in the community as a whole. The end of the division of society into the rich and the rest. A quite different approach and proposition. A revolution in the sense of a complete change in the basis of society. That, not reformism, is the alternative to toy town insurrectionism.