Lots of us SF-types like the idea of traveling to the Future (although, having now done so once myself -- the hard way -- I'm less sure), but why do we imagine the Future would want us? Oh, a few 21st-century Icemen, perhaps, as historical curiosities, but in our hundreds of millions? It would be like the greatest wave of immigration ever, but from the past into other people's Now. It might seem to them like sacrificing resources needed for their children to their great-great-great-grandparents. Counter-evolutionary, among other things.