First, no Olympics. Then, no Indycar. Now, no Ferris wheel?

Last week we learned that plans for a new wonderland at City Hall Plaza announced back in March are now decidedly less grand.

Back then, Delaware North’s proposals for transforming the long-maligned brick tundra were intoxicating: an iconic Ferris Wheel, a la the London Eye; a restaurant featuring local ingredients, beside a huge #BOSTON sign sure to be “the ultimate new Boston selfie station’’; an ice rink in winter; a summer “beach’’ with cabanas.

What a paradise it was going to be. But now, Delaware North seems to have realized what it should have known all along: Paradise is expensive, its logistics complicated — especially here. So the new plan will go forward without the Ferris wheel, its most ambitious and unique component. Delaware North, the company that owns and runs the TD Garden, says its three-year contract isn’t long enough to justify the cost right now. Further, tunnels beneath the plaza — which have been there all along — could make it structurally unsound. The restaurant that was to be the center of social life on the plaza has also been put on hold, because the site lacks electricity, plumbing, and other utilities. This, too, has been the case for, oh, forever.

Delaware North says the two projects might happen down the line, but that’s unlikely unless the city extends its contract. The scaled-back plaza will now host an ice-skating path, a beer garden, and temporary “chalets’’ that will house holiday vendors.

The winter wonderland could have been in place years ago. The downsized plan is strikingly similar to one proposed in 2014 by Anthem Group (minus Anthem’s restaurant): That initiative collapsed after the city, at the last minute, offered the company a one-year lease instead of the five-year one on which Anthem had been planning. The collapse has been investigated by federal authorities as part of a corruption probe.

So, here we are, minus the big wheel. And here is Mayor Marty Walsh’s City Hall with yet another much-heralded, ambitious idea that hasn’t gone as planned.

Now, the Ferris wheel is no great loss to the city. And we lost nothing when Walsh finally gave up on hosting the Olympics. Pulling the plug on the Seaport Indycar race was the right move, too, though it came too late.

It’s the pattern that is the problem here: an administration buying into ambitious plans without enough due diligence to discern whether they make sense.

Bless Walsh for working with the City Hall we have, for trying to realize the great potential of the building and the plaza (of which some of us are very fond). I love him for putting fake grass and plastic chairs on the bricks to make citizens linger, for his plan to light the building, which will look gorgeous.

But going with a plaza proposal that wasn’t achievable here makes you wonder about his judgment. Why choose a plaza proposal whose sexiest elements could not work within the constraints of a contract whose terms were clear from the start?

In an interview, chief of staff Dan Koh said the city chose Delaware North for “thinking bold about what could happen there. Ingenuity and ambitious vision is what we want to see in a vendor.’’ Fine, but shouldn’t ambition also be achievable? Otherwise, I’d like to suggest a network of canals, with gondolas steered by city councilors in straw hats.

Koh also said Delaware North is a reliable partner, “a known quantity’’ that has managed other civic spaces and is respected in Boston. (Another possible reason: It’s been a client of lobbyist and Walsh campaign strategist Matthew O’Neil.)

Reliable is good. But spending political capital on undelivered fripperies like Ferris wheels leaves less for important things like fixing schools. There’s a balance between boldness and caution.

This administration hasn’t yet found it.

Globe columnist Yvonne Abraham can be reached at yvonne.abraham@globe.com.