The results from that advice vary wildly depending on your 10 minute personal skills.
I know someone who happens to be extremely likeable that way. In this case, that person also ends up spending very little effort in fostering long term relationships, or doing the job well, but changing jobs becomes easy: Staying at a place is hard.
Someone else I know has Aspergers, so in a 5 minute coffee they appear to be 'off': unlikable. However, after a few months, care for users, coworkers, and technical competence show through: Instead of a very wide network, they have a much smaller one, but the people in it would recommend them for absolutely any job, warning others that the first impression of the dreaded "culture fit" will be very wrong.
Therefore, some people are great at this, are easily liked, and get very far on meeting for coffee. Others that lack those social graces, or are part of groups that are typically prejudged as incompetent, will fail with this shortcut. The solution is probably still networking, it just might be a very different kind of networking than informational interviews.