Good game design is quite a broad concept.
I don't see time limitations as an example of "good design", but that's just my opinion.
But I do, if properly applied.
Not even just time restriction, but taking into account the notion of passing time in general.
As for other simplifications, times have changed, now people don't have as much time and will as they used to.
I don't buy it for a second. People spend more time than ever playing games and not rarely disproportionate amounts of it on a single one.
