This certainly seems to have surprised everyone, but Rob Keyes has the background to the announcement over at Screen Rant:
When Disney Infinity first debuted in Q3 2013 the supply didn’t meet demand and production could barely keep up to maintain appropriate inventory levels at retail, so by the time Disney Infinity 2.0 came around – based entirely on Marvel – they over-produced big time. The problem was that the forecasts were way off, and using Hulk as an example, 2 million figures were produced with only 1 million being sold. That led to a drop in revenue reported in Disney’s financials.
Managing the complexities of supply and demand in the challenging toys-to-life category seems to have been a big factor, but it's made even more complex by what might have been Infinity's killer feature: The way it brought together different licenses, story worlds and characters in one game.
Despite Disney Infinity utilizing Disney-owned properties, there were a significant number of mind-boggling obstacles with licensing that caused all sorts of restrictions. In that respect, the business sort of killed its own business. Brands couldn’t exactly overlap with ease, so Marvel, Lucasfilm and other Disney IPs each presented their own squabbles. This is why story modes in the Playsets wouldn’t allow for characters from other brands to show up, or even with playsets themselves.
The Apple TV version of Infinity was effectively shelved a few months ago. For what it's worth, I'd given the playable "Battle of Yavin" demo a spin and enjoyed it, though when the full version launched I found it unplayable, with a control system that just left me frustrated and stuck. I'm a rubbish gamer, but my daughter had no better luck.
It's a pity too since the figurines are absolutely beautiful—with some of the most elegant renderings of Star Wars characters in particular that I've ever seen.