IIRC, cable companies, notably Rogers, lobbied the government to make small CATV systems illegal. Just prior to that, dishes started to appear on apartment complexes. Some of those buildings offered free TV to tenants as an inducement and cable companies didn't want to lose the business. The building owners could still apply for a BDU license but the regulations probably made it too much of a burden. What cable companies didn't see, of course, was the emergence of Canadian DBS systems just a few years later.