It's not really for no reason. Harper was highly sought after on this board all winter while I'd say the majority of fans here thought Anderson wasn't going to be apart of contending teams here. He swung too much, didn't get on base enough, etc. Meanwhile for like $24M less, Anderson's season has been superior so far.
I'd absolutely love Harper in RF too but let's not forget that Harper isn't even close to worth $30M per on the field. He's got a big reputation but he's just good, not great.