I think 'borderline cruel/dangerous' is overstating it (I do live in an 1 bedroom appt with 2 BOC and 1 BOM), but it certainly is true that if you have a working dog, you need to give it work. And place to expunge energy.
My partner does several dog-sports, and it seems that if you have on avg 30-90m training a day over the week, most of the day your dogs will just be happily tired and lounge around and sleep.
Or if she has more lenient training shedule, we do take them to run around in a field just outside of city like every two days.
The misconception is, that if you give a working dog big enough yard next to your house, it will be happy, but in reality you still need to train and work with it. If I were to exagerate, this kind of psychological neglect too can be borderline cruel and sometimes dangerous.
The bad thing is, even the owners might not realize. I heard several stories along the lines of "Our bordercolie is well fed, and well behaved, and has access to run around in a large garden, and take her with us every weekend on a hike, and then bites our friends child into her leg when the she tried to run away?" ... well, yeah, I am not surprised that a shepherd dog that isn't well trained and never worked would do something stupid like that.
My point probably is, that even in the sad story of the hard-to-manage presa canario, yeah, having it in an appartment didn§t make things easier, but I wouldn't see it as the primary problem.