I'm not really sure these threat scenarios apply when it comes to ransomware. Often ransomware attacks are not targeted but instead just the result of your standard drive-by attack or the classic shotgun e-mail approach, since usually university email listings are pretty easily scrape-able, especially if they're a Google Apps for Education (GAFE) university, as GAFE has pretty generous in-domain sending policies on email and there's an implicit trust in most people when they get something from an in-domain email.
So the initial point, while it may be true to some extent, is not really the common method of attack; the truth is that for the most part there is no need to really "craft" an attack against most users within a large enough organization. Just compromising one or two accounts or using one of many means to impersonate an official sounding account is often enough to get access to a few in-domain accounts. Once you have that, you can easily get past the majority of people's mistrust and get them to run just about anything you send them. When I did support for a small private university in the US, our GAFE accounts were constantly plagued by phishing and spam emails, and despite our best efforts to educate our user base, people just kept on clicking and giving out information. The entire process was basically automated from the attacker's side, as when we compared notes with other universities suffering the same issue, the emails sent out were verbatim copies, save that the university names were swapped out and a different logo.jpg was added to the emails for authenticity. Attacking a major organization really doesn't require a careful eye and dedication, just changing a few entries in some program and starting the process.
As for why to disclose? There's probably some degree of a necessary public accountability - I actually doubt that the university itself called up a paper and said "man have we got a story for you" so much as someone at the publication got wind of the information and plugged the university for a brief interview. Honestly, reading through the article, it's incredibly terse as far as actual details from the University as to what happened. Since it's a Canadian University, I'm not sure on their responsible disclosure requirements, but if it was in the US, I believe they have a timeframe in which they have to admit that student data has potentially been leaked.
Really, these sorts of impersonal attacks do need a lot more attention, since as recently as just a year ago, I found myself talking with somewhat major institutions around the US who had no real good idea how to deal with ransomware, (spear) phishing emails, and so on within their organization. Creating effective user awareness is really tough, since rather frustratingly, getting "phished" seems to be one of those lessons everyone wants to learn the hard way, or arrogantly thinks will never happen to them. We used a Twitter account in combination with a threat blog to try to notify our users, as well as warnings on our log-in page, but even after doing that for 4ish years we still had people giving out their information, and we had an okay-ish following on both.
I'm not saying that it was "good" of them to release that they decided to pay, but I also do question, given how easy ransomware is to deploy, whether or not more discretion would actually have a larger impact. Schools in particular are kind of over a barrel if/when they get hit by ransomware, and a lot of it has to do with poor data retention practices by both the University IT and by offices across the organization. Often times it's not just a mild inconvenience if someone's computer gets locked up by ransomware, you can potentially be irreparably damaging hundreds or more students' academic careers. Should this data be in a position that it can happen like this? Absolutely not, but that doesn't change the fact that it often is.