Corus has many otherwise viable assets, Nelvana included.
But like so many others in the Canadian landscape, those assets have been mismanaged.
Debt is an obvious issue here. Taking debt on for 'good' reasons is fine, to a point, but I would argue Corus took it on for the wrong reasons. It bought assets it couldn't afford, couldn't afford to invest in, and used debt to paper over the problems.
More broadly, Canadian broadcasters and film porduction/distribution companies have failed to grasp than the future is in global entertainment, and original content, not in being a licensee or distributor of the content of others.
Corus for years is/was a powerhouse in the home improvement space via HGTV. Its shows largely translated well into the U.S. market even when 100% Canadian, but they also can and did transfer those skills to develop/support U.S. made shows as well.
But they failed to take full advantage of that, even in that space, such that Corus wasn't necessarily the primary beneficiary of international sales, (many shows were independently produced and licensed); and they failed to follow that successful strategy with Food, Global or other properties.
They also let channels like Showcase whither, losing any sense of their 'mission' or 'audience' .........such that even channels focused largely on acquiring cheap content (no competitors in the Canadian space) saw massive erosion of viewership.
Many of those channels were originally Alliance properties...........which makes me recall fondly the impact of Robert Lantos who knew how to make money, but did so pursuing his passion for film/cinema and building a Canadian industry.
No one will ever say such a thing about the current crop of execs (and not most from the past either) at Corus, or Bell.
Robert, btw, is still around and still producing, but clearly w/o the same impact he once had with Alliance.
This is his most recent effort:
en.wikipedia.org