5 years ago when I worked at Saltlik, Most of the restaurant patrons were suburbanites or tourists, but mostly suburbanites. I'm not saying Stephen Ave needs to cater to cars, but suburbanites contribute significantly to the after hours business at those restaurants. what's the harm in leaving it as it is? or at least have one lane open. @darwink idea of one lane is a good compromise. It opens the mall up to more opportunity for pedestrians and who knows, maybe even bike lane, while still allowing taxis to come through. My own observation is more taxis than private cars use the mall, and there is a fair bit of taxi traffic dropping and picking up from the restaurants. As for having spots for cars to park, it's not needed IMO.
Might be controversial to say this, but we shouldn't care whether people who drive to Stephen Avenue are accommodated or not. To be honest, they are not the market for night time activity, and make up a ridiculously small percentage of the people who use the street. Same thing with 17th avenue. Let's stop trying to accommodate a bunch of suburbanites who complain about not being able to park or whatever, and actually focus on the people who are more likely to patronize this area (hipsters and yuppies who live downtown, or use taxis or ubers to get to those destinations). Sometimes I feel like our strategy for urbanism in this city is akin to Axe Body Spray trying to figure out how to tap the 70+ year old market. Or Saje trying to figure out how to get teenage males into essential oils. Maybe you are looking at the wrong market.