Consider it from a European perspective: The US under this administration is more unreliable than China. If Trump decides tomorrow that he's unhappy about something he'll pull some random other thing to bully the other side. You can't do business with that.
Rebuilding trust and foreign relationships is going to take a long time after Trump is gone.
I suppose it could be easier to approach a relationship in which the other party is simply known to be an enemy, rather than an ally which might occasionally take a left turn.