No they really aren't close enough together. For example, I know someone who moved from Zurich to Olten so that their girlfriend's commute to Bern would be reasonable. Now you have 2 people with 50 minute commutes instead of 1 person with 1h45 and another person with 15min. If there was a 30min connection from Bern to Zurich it would be perfectly reasonable to live in one and commute to the other.