The towers may be gone, but the ideals they represented are stronger than ever.
Fortunately the ideals they represented were much more successful than the buildings themselves. They were built speculatively. With so much square footage, it was always difficult to find enough tenants to fill the space. Only with the state of New York subsidizing the venture through the rental of 50 floors (or 25% of the lease-able space) were they able to be profitable. To make matters worse, there is currently a glut of office space in lower Manhattan. Most of the former tenants of the towers have signed long-term leases elsewhere. Any attempt to replace the full square footage in any redevelopment plan would likely be disastrous.
Nearly all of the first round of redevelopment proposals that appeared after the tragedy were somehow derivative of the twin monolith silhouette. Some were quite bad ideas. I won't dwell on them. More distance was needed. One thing we must understand is that we are not memorializing the buildings, but the people whose lives were tragically taken on that September morning.
What is even less inspiring are the practical proposals that are now coming out: four shorter towers instead of two taller ones, a low rise office park, a shopping mall.
Yes, the city lost a lot of office space... it lost a tourist attraction, a global symbol, a public observation deck, yes, it even lost the shopping mall underneath the plaza and the train station underneath that. We need something that can replace much of this and still respectfully memorialize the loss. But we need something that will be much more than simply the sum of its parts.
New York is desperately in need of a big idea. The World Trade Center was a VERY big idea, in both purpose and execution.
Like New York itself, the new "idea" must reach for the skies.
To do anything less would be to concede defeat.