Its been 7 years since 9/11. It's about time we let it rest.
7 years after Pearl Harbor, the germans, italians and japanese were our best friends again.
7 years after the end of the vietnam war, it was just the backdrop of The Deer Hunter and Apocalypse Now and not anything the average person mourned over anymore
7 years after Nixon resigned in "our national tragedy" we had elected Ronald Reagan to create endless tragedies to come.
It's time to pack it in and move on. Don't waste time and effort building a memorial at the former WTC site, just make a nice park and let people be happy there instead of miserable.
(footnote, the extremely tragic General Slocum Disaster which killed 1000+ women and children is almost completely unknown today, with only a very small memorial in a forgotten corner of a small NYC park to show for it.)