Assuming that's even true and again we don't know that. All we know is Deadline claiming a source (most likely from Sony) Deadline Article
I mean seriously, the "Source" is obviously Rothman or someone working for him...he totes saved Venom after Fiege took a shit on it!!!!
Also the "demand" wasn't Give me 50%! it was Disney saying let's be 50/50 partners in all things, i.e Disney/Sony would now split the production cost and the profit sharing and, probably marketing costs as well. It's not like Disney (assuming the message isn't totally slanted) held a gun to Sony's head and said give us 50% of the profit or else!
The first deal was Sony put up all the production and marketing costs and, held all actor/director contracts. Marvel came up with the story and executed everything (for the 2 stand alone Spider-Man films). Basically Sony were silent partners, while Marvel did all the work. In exchange, Marvel got to use Spider-Man in 3 of their movies and, got 5% of the First Dollar Gross on the 2 stand-alone Spider-Man movies.
Personally, I don't think Sony ever planned to renew the deal so, this is just them taking their ball and going home, while pointing their finger at Disney as being big meanies.
As for a Sony/Rothman being able to produce a great Spider-Man movie? I'm not holding my breath, he has an awful reputation with Comic Book/sci-fi movies.