Again, NIMBYism did not defeat this project! The market did.
I agree that many of the NIMBY arguments are frustrating and contradictory. You're worried about the loss of parking, but you're also worried about the amount of cars?? Make up your mind! Also, if you think your business is so dependent on parking, just move it to the suburbs. Chinatown has many competitive advantages in terms of location, walkability, vibrancy, etc. Parking is not one of those advantages.
That said, I do agree with one of the overarching concerns of the community, which is that Chinatown is being eating away at the edges by very unsympathetic development. Everything from the Harry Hays building to the Bow tower has been designed to squeeze out Chinatown from the rest of downtown. Even the new Parkside condo development, which is technically within the Chinatown neighbourhood boundary and makes a few aesthetic gestures toward Chinatown (namely the dragon gate bordering Sien Lok Park), has put its parking garages facing the Chinese Cultural Centre, while orienting its retail toward Eau Claire.
Calgary's downtown is sterile and terrible. Chinatown is one of the most walkable, vibrant neighborhoods in the city. I think it's a reasonable concern that Chinatown could be devoured by the larger downtown area and lose everything that makes it walkable and vibrant. I don't think this development would have done that, personally, but I can see why the community saw it as the intrusion of downtown-style development into the heart of Chinatown. They've also seen how in Vancouver entire blocks of Chinatown that were home to dozens of small businesses have been replaced with single condos that have two or three retail spaces occupied by banks and fast food/coffee chains.
I know a lot of people are going to disagree with me on this, but I think Elements on First offers a great precedent for developing the empty lots in Chinatown: mid-rise (8-15 storeys), aesthetic nods to Chinatown, small lots. The only problem with Elements is a lack of retail units. Housing demand in Calgary will never be so great that we need to cover literally every block in downtown and the Beltline with 30+ storey towers. Mid-rise districts have their place too.