That editorial judgement is exactly why most articles with no actual content are published in the first place - "We need to beef up this headline so it reaches more people"

Correct headline would have been "A handful of Fitbit users are..." but it wouldn't get clicks. The editors are to blame most of the time for doing a disservice to their readers.

An editorial judgement however absolutely should take quantities into account.

What were discussing here is whether the editor's judgement was poor and not whether there is some magical, exact "this is newsworthy" criterion.

There already is. In tech reporting, the criterion whether it can be fit into the pre-existing narrative of Big Tech being evil. There are similar numbers of people thanking Google for new features every day, but you won't hear about that.