Well that sucks. While I don't "hate" Lego in general (I mean I don't like how it horde's franchises and make them a parody of themselves) but Lego Dimensions was the one thing I liked and hoped it last and hoped would continue.
If it's the matter of modern console, they could of at least release a "Lego Dimensions 2" or make Lego Worlds able to use the Toy Pad to unlock characters and content.
The main reason was that it just wasn't popular enough to sustain. Unfortunately, Dimensions came out at a time when Toys-to-life videogames were on the decline and the consumer trend was moving away from that model. Add to that the higher cost of Lego, and it just made it hard for retailers to move without selling them at a discount. Even many Lego fans did not want to buy the add-on sets because they seemed too expensive. Much of the value of the sets were in the videogame content as well as the toys, but a lot of Lego fans just wanted the toys.
I really like Dimensions too, as it Lego-ized many IPs that I grew up with, and the amount of content in the game is staggering. It was it's own game platform in a way and there were a lot of story packs that probably would have been stand alone games if Dimensions didn't exist.