Do people generally expect to spend more money these days?

Not according to the Federal Reserve, please look at the links I posted, particularly this one. Median real income has been steadily rising since at least 1985. That is part of what is fueling the lower savings rate - people have more and are confident that they will have even more in the future, so the perceived need to save is diminished. Generally speaking, a kid who gets a candy bar every day, guaranteed, will eat it more quickly than a kid who gets one candy bar per month, maybe.

Yep, there are a smorgasbord of social and economic drivers behind the trend.