Its limitations are those of the physical universe: it won't let you play with some really wild ideas that aren't possible, but are fun to speculate about.
Stanley SchmidtThere may be something to the suggestion about the pace of technological change intimidating writers, though - it's been awfully hard to keep ahead of real developments.
Stanley SchmidtI think the rising and falling popularity of areas like hard SF and far-future SF is, to a considerable extent, the same as any other fashion.
Stanley Schmidt