Regardless of who you see walking out of the store, if you draw a 3-5 mile ring around University and Markham, you will see that the income, household income, ethnicity, etc. do not fit in with the Apple model. That being said, shops have been doing well in the area inspite of the demos (save Lewis and Clark, which is poorly merchandised and operated). In today's economic climate, retailers are not taking flyers on locations that don't fit specifically into their growth model.
Ask the developers of Park Avenue about the interest in their project and current leasing progress if you don't believe me. In 2007 they were on fire with interest from tenants. In 2008, they are lucky to get a national retailer to return their call.