Forcing people who have broken their new iPhone's screen to trade it in for a refurb because no third party repair shop can swap out a serialized display isn't user hostile?
A company does not make decisions based on a pure "will to be evil".
They probably think that the reputation hit from not allowing repair is less damaging than the reputation hit from users dissatisfied with repairs. Other design choices can be for cost cutting in design or production.
So sure, it is not nice for the user, but the reason is not a desire to spite users. They likely simply think the additional costs, tangible and intangible, of being repair-friendly are not worth it.