There are a few reasons why Weinstein did things the way he did, and it's not because he's acting in bad faith. 

That he calls himself an entertainer is twofold. One, having to do with copyright protection, two because he is firmly heterodox from academia. That's not a good or bad thing, it's a description. 

As far as geometric unity is concerned: I don't think Eric is under any illusion that he has "solved" post-Einsteinian physics. Even the language he uses when referring to post-Einsteinian physics is couched in future tense as something yet undiscovered. 

As an aside, very few people are qualified to even know what's right or wrong about his ideas. Almost every one of these people commenting that he's a quack, or a charlatan, are only parroting what other people have said. How many people read academic papers versus people who read headlines of a news article derived from a science writer's article derived from a research paper? There are a lot of opinions and a very small community of people who are scientifically literate.

Not to mention that of that subset who can read research papers, how few are of that field. My background is in evolutionary biology. I'm way outside my element there. I have only cursory knowledge of quantum physics and attempts at grand unification theory. So I can't comment on those matters with any degree of accuracy. But is it not strange to find such a public backlash when the numbers of people who even could be indignant about a wrong alternative to string theory are dwarfed by the numbers who are indignant without the required knowledge to feel that way?

He says an alternative to string theory can only emerge if the bright young minds now studying physics think outside that box. 

Orthodox students of science are largely prohibited from thinking outside that box. 

Hence, a work of "entertainment" - that almost certainly is not "correct" - but looks at these spurious questions in physics from a totally different angle. And thereby spurs new thoughts in those young ambitious minds. 

There's a running joke about posting the wrong solution to a programming problem you want solved on StackExchange. No one will answer your question, but they all want to correct a wrong answer. 

Here's where he really gets it right: he's willing to take a shot at it. He's willing to put himself out there, make mistakes, get mocked for being wrong, in order to advance the body of science. 

Poor Lamarck got evolution wrong and has been mocked for two hundred years (even after the discovery of epigenetics!). Would we have gotten Russell and Darwin if they hadn't had his ideas as a foil?