Katz may have set the trend for Alberta but he's just following a trend that's been ongoing for a while in North American. Times are changing and the reality is that most new sports facilities will either be built with some level of public financing or not at all.
As for the idea that these facilities are never worth the investment, I'm on the fence. This to me can go either way with everything riding on how it's done. Edmonton has great plans for their new arena and how to integrate and leverage it within it's new location. With the way they're proceeding I believe that it will bring about massive positive change for that city and it's downtown. If I lived in Edmonton I would be 100% for spending public money on the thing because I think the benefits will be there.
As for Calgary, I would be against spending public money on a new arena because, unless someone can show me otherwise, I don't see the same benefit available to Calgary.