Early on the uBeam folks built a pretty low power acoustic transmitter/receiver that could, over a relatively short distance, actually deliver a charge to a phone. Not a super useful charge but, you know, something. Based on this demo and some handwaving (and maybe a bit of math) they went out and said "something that delivers more charge is possible. give us some money and time and we'll work out the engineering." Mostly they raised money on this. Likely without a ton of due diligence.
The actual engineers working on the project (including the one in this "spat") at some point realize the actual limitations of what is possible physics wise. But they still think "a useful product is possible here." Maybe you can deliver enough to charge a phone overnight while it sits on your coffee table. That could actually be cool? Maybe?
Meanwhile the PR machine gets going and, as so often happens, the exaggeration kicks in. Those that haven't been here themselves look at it and see LIES. I have a more nuanced view. The press can misunderstand and distort things on their own side. And then if you don't refute it fast enough then you almost have to support it. Not saying this is ok, but I can see how it happens. The statements about what is possible just get out of hand and then you're stuck with them.
So behind the scenes some of the engineers read the press and go "WTF, this is insane, I'm out!" Others say "well, that's all bullshit, but this overnight charger thing could be useful. So I'm gonna keep my head down and work on that. If we can get it to the point that we can release a commercial product then we'll see what the actual market is." Inevitably actually building a commercial product takes longer than you think. These are just normal engineering delays. No "trying to defy physics" type delays.
Which brings us to the present day. Almost certainly what has been hyped is not real. But there might be something less good there. Maybe. If they can balance the tradeoffs between input power, actual power delivered, distance and safety. That's real engineering work right there.
All just speculation. Take it for whatever it's worth.