I don't think an observation deck on the top floor would really be that big of a draw here. Sure, it would draw some people (mostly tourists from nearby hotels), but we're not really a big tourist or business travel destination. Limited impact on any ground level retail and hospitality
hmmm, I'd argue that one of the reasons why we're not a big tourist destination is because we overlook opportunities like that one to add a tourist attraction.
Take that top floor (or the one below), make it into an observation deck, put a nice restaurant that is not necessarily crazy expensive (like the Calgary Tower) and people will come. May not form huge lineups like at the CN tower, but would 100% get some steady flux of people, and create a little bit of buzz that could grow into something more, and add a new, different, kind of destination to DT.
It's the little things that, compounded, will help turn DT around.
Edit: Edmonton is the only 1M+ city in Canada without a public observation deck.
Toronto - CN Tower - 346m
Montreal - Olympic Stadium - 165m
Vancouver - Harbour Centre - 168m
Calgary - Calgary Tower - 191m
Ottawa - Peace Tower - 93m
And both Winnipeg and Quebec City also have one, CMHR Tower at 100m and Observatoire de la Capitale, at 132m respectively, which makes Edmonton the only major metro area in Canada without one, despite having the bragging rights to the tallest building outside of Toronto. Sounds VERY counterintuitive.