It is a trend in a trend based space and also for practical reasons—a lot of old logos do not scale particularly well to a tiny profile picture. I mostly hate

It is a trend in a trend based space and also for practical reasons—a lot of old logos do not scale particularly well to a tiny profile picture. I mostly hate this trend, but it is in part a response to the overly playful logos. Look at the trend towards and away from skewmorphism in UX. Very similar here.