Let me preface this by saying that Braben is a BRILLIANT engineer. He CAN deliver and HAS delivered hugely successful products, just take a look at the Raspberry Pi.
Everyone loved Elite, it has a mythological status similar to Master of Orion, that you can't make a vaguely similar game now without it being dubbed an Elite Clone. Great.
But Elite 4 was promised for decades. There was no lack of support, no inkling that there wasn't a market for games like it, as games like it came out every few years and sold like hotcakes. He just never agreed to a funding deal. I'm not convinced that there was no funding, or that traditional publishing wouldn't support the game -- just that it wouldn't support it in the way he wanted.
Now, this is the crux of the thing. A leader isn't someone who gets their way. A leader is someone who empowers others to take successful actions towards a goal. So what I mean is that I'm just not convinced that he can lead a team to make this game from the ground up. It seems like he can produce great things, but that he probably is not the right kind of guy to actually be at the helm.
I'll be enthusiastic about being proven wrong, but if single player support is already gone and the preview videos already are displaying a disappointing level of arrogance, well...