IMO this is one of the best articles the Post has written! I'm on the keep side, but you are absolutely correct that the final decision made will not define Toronto's future. Old Toronto has lots of excellent waterfront spaces, though most of them are a pain to get to without a car. This one stretch will not make or break the city's future.
The real push for its removal is from developers, period. The hybrid option provides more than enough new space for development, but it is not enough to satisfy the neverending needs of uncontrolled capitalism. How many parks and other public spaces are included in the remove option? They can't develop on environmentally sensitive lands on the greenbelt, so they are going to build on public infrastructure instead, The funny thing is that the reason why developing here is so lucrative is that it is expected for public dollars to remove the Gardiner for them. If they had to spend their own money... well, let's just say the lobbying voices supporting this option would go real quiet real quickly.
And of course, the east end of this plan would still be very much cut off by the rail tracks. This is not an exaggeration. Not including the DVP, the next street going north of the tracks east of Cherry is Booth, which is 1.25 km away. A street could be put in about 1 km east though, but that is still a large distance without through streets keeping Toronto separated from its waterfront. If the Gardiner does go down, expect CityPlace East rather than a new Harbourfront Centre.