Who said anything about scrum? The comment was about "agile," of which scrum is only one possible implementation[0]. Sprints are not only found in scrum, but also in other agile approaches, like kanban.
Two-week sprints seem to be the default in tech, although I've worked at a company that very successfully used one-week sprints. That's completely separate from how strictly companies try to follow "scrum," if at all. I've run into kanban more often than scrum, personally.
0. https://en.wikipedia.org/wiki/Agile_software_development
