You, (like many people, including the organizers of many conferences) keep conflating <i>socializing</i> with <i>collaboration</i>.  I tried to make the difference clear in my original comment, and it was also the point of the linked article.  Being friends with someone isn’t the <i>only</i> way to collaborate with them.  It is simply <i>a</i> way to do it, and <i>if</i> you want to collaborate <i>that</i> way, <i>then</i> socializing is certainly important to keep that friendship alive.  But if I want to collaborate as a <i>professional colleague</i> instead of as a <i>friend</i>, then no, I don’t think I should be expected to socialize with great masses of people in order to simply collaborate with some of them.