Yeah, not sure what you guys are seeing that's giving you pause? If anything, they went from an unattractive business model (Frontiers) to a much more attractive sequel business model (Torchlight 3).j
Edit: re: the last trailer. I used to dismiss base building type features as unnecessary and wasted dev time that came at the expense of content and more desirable features. The reality is that it's pretty low cost development-wise as you already have the assets and the tools as part of the dev kit. And as a player, I like having a trophy area to show off my accomplishments.
Edit2: Also, historically Torchlight has been $20 at release making it pretty easy to pull the trigger. When Torchlight 2 came out I actually bought two copies and gave it to my friend so I'd have a buddy to play with.