Plus -- the original Twin Towers' designs were thought up back in the 1960s... It's pretty easy for designs to quickly become outdated.
I never got to go to NYC prior to 2001, but I know I would have greatly preferred staring at the twins over the then-Bell building. The new 1 WTC is the same size the original twins were, and I've seen 1 WTC daily on my last couple visits to NYC... And I simply can't take my eyes off it whenever I see it in person. It's really, Really, REALLY freakin' massive. The latest pic NYGuy posted gives you a pretty good sense of the scale of the new WTC buildings. 4 WTC is, what, 400 feet shorter than 1 WTC? And it's effing ENORMOUS too. 7 WTC is literally next to 1 WTC, and the latter just DWARFS the former. Un-fucking-believable to witness for yourself.
I live in North Dakota... I believe ND is home to the tallest capitol building in the US (19 stories high), and it has *nothing* on 1 WTC, although I think the base of it is wider than 1 WTC is. You just feel so tiny next to it! And I know the original twins had that same effect on people.
I, myself, wasn't crazy over 1 WTC's design, but it's grown on me and I adore it. Simply stunning to view in person. It's so tall, the sky just swallows it right up. When I see skyline pictures with the new WTC buildings in it, I always think, "This just feels so... Right."
There's so much to look at!