Yeah, I avoided that feeling at first, but I think its a bit of the art style being a little too cartoonish. I know its stupid, but when I see hack and slash + cartoons I just start thinking of browser games.
In torchlight I think they needed to work a wee bit harder on differentiation of the characters and places you visit. I couldn't name one character from torchlight 2. (And I am on act 2.5)
Your second paragraph is very relevant to my feelings. "Same actions, new background" is pretty much how I felt when playing. I think I may have gotten to act 2.5, too.
In torchlight I think they needed to work a wee bit harder on differentiation of the characters and places you visit. I couldn't name one character from torchlight 2. (And I am on act 2.5)