I wrote a nice long response earlier this morning and it appears the forum Gods ate it.
When I lived Downtown I too did most of my shopping at Christown. At the time there was a Target nearer on 7th Ave and Camelback, and I went there a fair bit. It still baffles me that even with the low population downtown that we don't see more large scale retail Downtown, Im sure the residents of Coronado, Willo, etc. would likely prefer to go Downtown instead of out to Christown (its slightly closer as well as being more interesting). At the very least Id think Park Central would be more of a retail hub than it is, there are very expensive (and occupied) residences all around it.
Retail of course follows rooftops though and until downtown has more people living in it, it'll continue to be a problem. I'd assume we won't see more people living downtown until we have more people working downtown. Our CBD is very small compared to most cities our size and this is a huge problem. The more people who work downtown, the more 9-5 businesses will exist. The more people who work downtown the more people will come to like downtown and see that its safe and clean and an OK place to live. If we vastly increase downtown workers it seems to me by the very nature housing will have to follow eventually.
Its disappointing that some dolts like you ran into at the Roosevelt meeting want a boutique only strategy. That'll never happen and if it did, it would be doomed to fail. Look at the Galleria or CityNorth, boutiques are fine, without anchors though they can't usually survive.
To me what the City of Phoenix desperately needs to do is try to get more large firms to move Downtown. The first order of business should be to try to attract firms like PetsMart, CSK Auto and Cold Stone to move downtown, specifically to the West Van Buren corridor.
Like I've said West Van Buren between Central and 7th Ave is Phoenix's best hope for a retail street downtown due to being zoned for large buildings that will have large floor plates and thus could house large anchor retail like Pennys, Macys, Khols, etc.
With the potential Heritage Trolley line running up and down Lower Grand, if it was extended down Van Buren to connect to a (totally revamped) Central Station it could really make West VB something special and unique. And being unique and different is what any downtown retail area is going to need to draw people from the 'burbs.
Here's a quick Google map I mocked up of how Id hope W. VB would develop:
Red= New retail
Yellow= Adaptive reuse of warehouses, boutique retail
Blue= Office
Grey line= Trolley
*Note the office could be over the retail, there's just no way to denote that 3 dimensionality on Google Maps.
Hotel and some housing could be there as well, but I was trying to mostly show the office and retail. Then Lower Grand could continue to develop as the funky boutique shopping street that so many Downtown hipsters want and would likely see spill over from West VB and people riding the trolley.