It's the way of the future. It's also the way of the present. People here claim that they want Calgary to be a world class city - world class cities have these stadiums and not NHL teams.
It should also be noted that these outdoor soccer stadiums attract concerts and events that don't always fit into a standard size arena.
Massive outdoor stadiums that don't have an MLB team are much, much bigger white elephants than arenas. Not even close. How did the investment in world class Olympic stadium work for Montreal?
You can fill an arena 300+ days per year, you can fill a stadium at 60,000+ in this country maybe once or twice. Maybe. That's also with probably fewer than 50 events at the very most that would draw any kind of crowd.
There are other cities in the country with world class stadiums that don't get used, not sure what would make Calgary different. Agree that Calgary needs one because McMahon would be an embarrassment even for a 3rd world country, but there is no way its a better taxpayer investment than an arena.