Maybe because such activities generate noise? Noise bylaws are a thing in most urban places in Canada, and most leases have some clause in them about excessive noise and disruptive behavior that prevents other tenants from enjoying their own space.
At least here I have the right to call security for noisy neighbors (ie. people who don't understand that it's really not okay to have parties at midnight or let their kids jump around on a carpetless floor above another suite at all hours).
And before anyone asks why I would call security rather than ask them nicely to be quiet, remember that in my first year in this suite, a tenant tried pushing in here after midnight and the cop assigned to the case turned out to be useless. Ever since then, I've been reluctant to confront neighbors (at least male neighbors) alone. This isn't the most dangerous place I've ever lived (that "honor" belongs to the place where the cops' presence was a semi-regular thing, drugs were going on, and a woman killed her partner in the next block), but I'm not going to take unnecessary chances.
