The Hub may be facing hard times, but there is one thing the city still produces in abundance: Pipe dream developments.

It is just much more fun for the city’s legions of neighborhood activists to endlessly debate grand real estate schemes that will never get built than to focus on something more practical.

It certainly doesn’t mean things don’t get built around here, because a lot certainly does, such as the aircraft-carrier-sized convention center and the State Street tower.

But the real fun comes in debating plans so grand – and so economically unfeasible – that they are unlikely to ever make the jump from paper to concrete, steel and glass.

This peculiar and somewhat exasperating trait comes to mind amid the debacle of what was supposed to have been a centerpiece redevelopment project for Roxbury.

City Hall put a key development parcel, P-3, out to bid in early 2006 in hopes of bringing some downtown-style development to a desolate tract of debris-strewn land near Boston Police Department’s Roxbury headquarters and Ruggles Square.

But in true Boston tradition, the local businessmen with the money and a viable plan were rejected in favor of a grandiose vision of a nonprofit arts complex, complete with a downtown-sized price-tag.

To be fair, it was certainly a noble idea, with plans for a 60,000-square foot museum for the National Center for Afro-American Artists, while an old health center was to have been converted into an arts school.

But nearly two years later, the dreamers are out, having missed at least two deadlines to produce any evidence whatsoever of some cold hard cash to back their $350 million vision.

Now who would have guessed that outcome? Of course, it’s a decision being blasted by some city councilors, including Chuck Turner.

“They failed to meet the requirement to let us know how they were going to finance their development program,” John Palmieri, the new director of the Boston Redevelopment Authority, told me.

Of course, now it’s back to square one, with the BRA talking about eventually putting the key development tract out to bid again.

Good luck with that.

Now if this all sounds so familiar to those in the local development business, well it is. For Ruggles Place is just the latest in a long and illustrious line of pipe dream projects that have triggered endless hours of debate in Boston at the expense of more realistic proposals.

If you are looking for a pipe dream, the Hub’s your town.

The Ruggles Place proposal, with its striking mismatch between lofty ambition and empty coffers, bears an uncanny resemblance to the long-debated Garden Under Glass.

That was the Massachusetts Horticultural Society’s proposal to build a $100 million-plus glass-encased botanical garden just outside South Station. The group never managed to raise a dime, but that didn’t stop it from stubbornly tying up a prime tract of real estate for more than 15 years with this expensive fantasy.

Of course, developers can play the pipe dream game as well. Frank McCourt spent two decades talking up various plans to recreate Back Bay or even a Parisian boulevard on South Boston’s waterfront. Of course, nothing ever got built, though McCourt did manage to sell his sprawling tract of surface parking lots a few years ago and buy the Los Angeles Dodgers.

The Fan Pier project, or at least one office building, is now under construction after 25-years of debate. But I am still waiting for that marina, the harbor front shops and eateries, and all that waterfront parkland the project’s original, and now long-gone, Chicago developers pledged back when they won city approval back in 2001.

Then of course, there is Tommy’s Tower, Mayor Thomas M. Menino’s vision of a thousand-foot skyscraper that, even if the billion-dollar project could have been financed, would have required emptying out the rest of the financial district to fill it. Still, I liked idea of a park in the clouds at the top, though maybe someone should have consulted the FAA first about flight paths from Logan.

I could go on and on and on, but let’s get back to our still undeveloped tract of potentially prime land in Roxbury.

That group of local businessman looked like early frontrunners. It was led by Richard Taylor, a local minority developer and former secretary of transportation in the Weld Administration. It also included backing by former Lakers’ great Earvin “Magic’’ Johnson’s California investment fund.

Of the contenders for the site, it was only Heritage Commons that was able to commit to inking a not-inexpensive deal to lease the eight-acre site from the city at $3 a square foot.

Taylor and crew won an early nod from a city-appointed community panel.

But then the businessmen did the unthinkable. They changed their plans based on some pretty big shifts in the real estate market. An initial emphasis on housing later gave way to office space as the residential market weakened. A jazz center and a hotel put on hold.

But that pragmatism apparently hurt the group’s chances. The community panel, in the spring of 2007, awarded the deal to Ruggles Place, citing, among other things, the consistency of its vision.

Of course, the other consistent factor was the group had no money in the first place to implement its laudable, but expensive plans.

Still, it took another year for city officials to figure that one out.

This summer, a year after winning City Hall’s nod, the would-be Ruggles Place developers failed to meet a key city financing requirement. Not to have the money in hand, mind you, but rather to demonstrate a viable plan to pay for its proposal.

After a second deadline came and went this fall with no evidence of any progress on the money front, city development officials pulled the group’s development designation for the Ruggles site.

I guess that’s an improvement of sorts. They could have let this drag on for decades, as is the tendency with such pipe dreams in Boston.

But it’s pretty clear an opportunity was missed here. One that, in this economy, won’t be coming back anytime soon.