In London the argument for companies being in zone 1 is that meeting with people from other companies is easier. So for the few who have external meetings the entire company has to drag itself every morning and evening through the overcrowded, unpleasant London underground, arriving at work late, flustered, or miserable. What a way to start the day. If the companies moved only slightly out of centre, zones 2 or 3, the majority would be happier, and the few who meet outside would have a 10 or 15 minute, relatively pleasant, tube ride to get to a meeting.