Fair enough, but some of the worst offenders of this aren't really targeted at children or something they'd be interested in. The new Github UI (which I adore,

Fair enough, but some of the worst offenders of this aren't really targeted at children or something they'd be interested in. The new Github UI (which I adore, besides this particular issue) is a really bad offender for example. If you go to your profile page, there's not a single not-round border. The exception are the little squares showing activity, which makes it even worse because in the caption underneath they are rounded. What happened there?