And you know why that is?
Because these cities understand how important image is to getting people to ride public transportation.
Boston has always failed to make a link between image (self promotion) and ridership. Boston doesnt have to look like the new dubai subway, but if theres a FREE way to imrpove image, they need to take it. And today, that means curved trains/buses.
I've heard this argument applied to US cities before (Chicago, notably), and it may be true for Boston as well, but in my opinion the Bredas aren't a good example. I've been living away from Boston since roughly the time they went into service, and I rode them last month for the first time in a while. They look new, and while they might not be as sleek as the new designs (or the Kinkis for that matter) they look handsome.
It's interesting that the word "fugly" was used for the Type 8s, because that's exactly the word I'd use to describe the proposed Type 9s, and definitely the word I would use for many of the models in the countries that "get it".
When you're trying to sell a brand new transit system as the way of the exotic future, I suppose it makes some sense to have the vehicles resemble insects. In Boston, though, we know exactly what the Green Line is... and isn't. There has been light rail and streetcars in this city for over a hundred years. I don't think you'll fool anybody with curved Green Line trains any more than Toyota would fool anybody by putting a giant spoiler and futuristic face on the next Camry.
Indeed, when I see low-slung curvy trains, I think of slow-gliding streetcars in mixed traffic, not heavy mass transit replacements going 45mph (I know that's only one line, but still).
If I loved these designs, I'd have no problem with this. Since personally I don't, I see no reason to emulate worse designs than we currently have. The T in general does need to improve it's form factor for image enhancement, though ("Driven by Customer Service" is as bad a slogan as has ever been thought up).