practicality
Of course, it's not always feasible to guide a client (or friend) through a platform migration. I understand that better than most, having been involved (both professionally and personally) in a number of such migrations, and a number of discussions about the benefits and detriments of such a migration that resulted in nothing changing.
I was just commenting on a best case scenario, where people are operating under circumstances where the migration really is the best option (far more common than most people think -- almost always, in fact), are willing to listen to reason and give it a shot (depressingly less common than it should be, though still not entirely uncommon), and do not essentially set out to sabotage themselves once things start (surprisingly common, all things considered).
