In my part of the world, everyone that can, will use flyers, two at 2k.
So almost everyone has the opportunity to "exploit" the rules and feast on unsupported flanks. Which brings a status que and thereby a silent agrement that says it is ok to "do so", if the opportunity immerses.
On "topic", if a unit in one part of the movement phase is not allowed to reform, and there is no penaltys or battlefield reasons why not, and another unit in the same movement phase (or any other) is allowed to reform, which is also without the same "restrictions", why should their respectively rules differ?
The written answer "balance of play", i do not buy that, it is not a reason, it is a by rulewriter (and testplayers) decided text to avoid a problem without addressing it in a logic, battlefieldish way. So to speak.

How about, "the unit faces the direction in which it homed back, and by the first order it gets it can only move 100cm 'minus' home distance"?
(100-D6x10cm, D6=result of home back)