It just depends on what you want to do when you're in Edmonton. During the summer, there's a lot to do. We've got a huge river valley, a lot of biking trails (the biking is better here than in Calgary...you can be at a trail in 10 minutes, and you don't have to load your car up and drive anywhere to do it), a lot of festivals (more than just about anywhere else in Canada), a lot of restaurants (one of the highest per capita in North America), a lot of movie theatres (among the highest seats per capita in North America) and more live theatre than anywhere else in Canada, and possibly North America. We're home to the world's biggest mall, and it has an indoor amusement park.
If you're willing to drive a little, there's a lot of camping and lakes within a couple hours of Edmonton. Jasper is only 4 hours away, if you like road trips.
Sure, there aren't a lot of big museums here, or grand churches or anything like that, but there's lots to do in Edmonton if you're that kind of person. Most cities seem boring after you've lived in them for a while. Even Vancouver is pretty boring after you've been there a few years. If you want to drink a lot and go to a lot of clubs, definitely go to Montreal, or Vancouver, or Toronto, but don't say that there's 'nothing to do' in Edmonton. You're just not trying.