It's a vote killer for sure with the general public who think the labour membership is a bunch of Stalinists/Trotskyists(God the British media is stupid). But the idea itself isn't awful, there would have to be constraints, at least a 50% voting participation for example as, you wouldn't want 15% of labour members deciding such a important outcome But these sort of issues are natural when you're trying to democratise a political party.
Also I'm not sure how many times the UK needs to blow the shit out of poor brown countries(And thus in some cases turning them into slave states)for people to realise the current system is beyond shit. The idea the British state listens to experts is simply untrue, Theresa May husband who acted basically as a adviser to her benefited from the UK bombing Syria, Blair had no idea about the Iranian coup in 50's. I think people have vastly underestimated how fecking stupid politicians and the war on terror has been
Burton may give car crash tv interviews but he's correct on this point
Its helps if people read the article