Something like that needs a much different "locomotive profile" than a train that entirely stays on grade-separated rails. A tram that can be stopped at a stoplight like a bus needs visibility from the cab so that the operator can ensure there isn't a child in front of the train before moving.
This means you end up with a front that ... looks like a bus. Compare to high-speed trains, or even subways (subway operator visibility is often pretty low).
(American rails are separated into "light and heavy" where heavy rails have some very significant requirements due to sharing the lines with freight, etc. And the freight locomotives are designed to protect the engineer in the case of a high-speed grade collision. Something that is not supposed to be possible with euro/Japan style high-speed rail; a ducknose hitting a semi truck would push the truck right into the cab.)
