Why fix what isn't broken?
OK the Flinders Street interior is sadly neglected and under-used but it has also been allowed to reach that state through under-funding.
Put a roof over the platforms and the next thing will be air rights up for sale and another sky-high block hiding the trains.
I also happen to be heartily sick of the drunken, slop-sided angles certain contemporary designs are riddled with. Federation Square is one of the worst offenders. The cheese straws on the Tullamarine Freeway are one of the most visible. I work in a building where not a single interior window has a right-angle to it and all seem randomly placed with no thought as to the function of windows namely to admit light and to permit convenient vision of what lies beyond.
As such the designs proposed are at the best uncomfortable and - if they were to become reality - would most likely perpetuate the nonsense which is this "contemporary" design for which the redoubtable Mr. Bear has a shorter and far more succinct description. With which I wholeheartedly agree.