This will depend on the building of which you speak. There are lots of high rises in Chicago that have plentiful rental parking, or spaces not deeded to a particular unit that are sold separately.
However, I've seen people walk away from a unit they love if there is no parking available at all.
Then again, there are some buildings located in areas where many people don't even own cars due to the expense of parking.
I hate to be so nebuous, but it really depends on the situation, building and location.
If you are an owner and want to sell a unit with no space, be sure to proactively check the parking situation in your building, or, at the very least, in very closely surrounding buildings, as alternative options for potential buyers. If you are considering buying a unit with no parking but are worried about resale, I would do the same thing before writing an offer.