I think it's good advice for beginners or those wanting to learn. I know a *lot* of beginner photographers who will stand in the same place and take 4 or 5 shots on auto then be unable to choose between them. That sort of thing is really difficult because the shots are all actually the same!
Imagining that you have a roll of 24 or 36 can really help some people. It forces them to ask "do I really want this picture?" or "what is it about this angle that works?" or - as Steve said, and perhaps most importantly "why am I taking this?"
Of course, like most internet articles, it won't help everybody. Daughter's graduation or other family event? F1 car overtaking an opponent on a corner? Finches jumping around on a feeding table? There will be a long list of exceptions - most of them - as Dave alluded to - restricting any sort of planning time.
I don't think film is a good comparison. Film isn't inherently slower if you're using the right equipment. Eye AF, 7FPS, and a 70-200 f2.8 on the EOS-3 isn't exactly "slow" and is probably good enough for all but the most demanding of environments.
If it gets people thinking more about why they are taking the picture though, that can only be a good thing.