I see it both ways.
I know that the Atlanta Braves moved out from downtown to the 'burbs and had a ton of extra land available to build restaurants, bars, hotels, etc. Light rail goes right to it. It's supposedly awesome. That's not always possible, though.
Downtown venues just usually have that functionality built-in, which makes those locations more desirable at least from a fan's perspective. We want the "total experience".
Could the Bears' ownership offer that in Arlington Heights? Having family from the area, I know exactly where they're looking to build and from what I remember, it's just the regular-'ol 'burbs and they'd need to build up the area around it to have any desirability.