Well, I think it's more likely that the fact that it's a notebook will make this less of a PR issue. HN is kind of a unique place, but out in reality land the set of people who take their 15" notebook with them everywhere, including the airplane, is much smaller than the number of people who take their phones with them everywhere. So it's hard to capture the public imagination with a notebook.
Apple releasing a new phone is an event not only for a lot of developers, but also for your average teeny bopper and housewife.
Also, most people aren't going to grab a camera and start filming when their laptop catches fire in their house so they can post it to the internet. That limits the number of videos like this you'd expect compared to a similar smartphone fault, which is more likely to happen in public with other people standing around idle that might film it. I'd venture a guess that this is very far from being the first such fault in four years, especially given how willing Apple was to announce a recall.
Also, I think the fact that Samsung's first fix turned out to not fix the issue at all help blow the problem up from embarrassing launch snafu to major fail.
All we know is that there's one incident, and now there is a recall. If there was no endemic issue, there should not reasonably be a recall; there's been handfuls of stories about iPhones burning up that have not ended up resulting in recalls, presumably because they're isolated issues.
I don't actually know how many Note 7's burnt up before they recalled, but I don't think it was ever very many. The main difference in this case is whatever issue exists, it was relatively benign for at least four years, which I agree hints that the issue is far less severe. But of course, no less dangerous.
Apple releasing a new phone is an event not only for a lot of developers, but also for your average teeny bopper and housewife.
Apple releasing a brand new laptop is just...
not.