I think it is both depending on the situation. I would say that I probably lean toward being a sandbox player so that may be why I like it. I like being able to turn off elements that I don't want and choosing what to do. (I was not someone who bought Vampires and then complained about them). It's important to keep the sandbox element to it but the game does need "more to do". I like keeping that completely optional not to be easy but to keep it a sandbox in which I can do what I want, whatever that is.
For example, I've liked how the StrangerVille challenge ended and I could decide what to do which in my case was just to include the world in my game. I get that people want harder sides of the game and I am open to that but I also like being able to decide how my sims will react in a given situation. I'll say that while the game can be kind of a drama simulator there is definitely a general life simulation element to it. For example, a player can minimize drama in the game and just play with the various elements, gameplay objects and scenarios that have been coming out. Sometimes I basically do that so I'm also a simulation player.
To be less boring, I do think these optional challenges are good examples of the way forward. They could also give us some more game events that have unpredictable effects. More recently we've gotten pop-ups that prompt sims to get married or relatives to have a baby. I'd kind of like to still keep these optional and sometimes I've ignored the marriage one. A tricky side of this is just that players want to do different things and sometimes get offended by different things so they probably try to cater to as many as possible.
One of the biggest issues that I think is a factor is that I think this version is also tailored a lot to children playing the game as well. A lot of the humor is very silly and most of what is added to the game can basically be geared to kids. Likewise we probably don't all want the same themes in our games. It just results in gameplay possibly being very watered down but I think that keeping an open-ended side to the game is important even as it would benefit from more gameplay.