I'm of the Janet Jackson school, "What have you done for me lately?"
Wow, that's harsh. Players are going to slump. And, really, it's not like Harper is having a totally bad year. The guy is going to end up with 40HR and 100 RBI, roughly. I know his BA and OBP is down but that can change.
It's not really about what he's done in the past when deciding if to sign him or not, it's what you think he's going to do in the future.
Again, I just think the guy is super scrutinized and some fans just don't like the highly hyped, highly paid players with a bit of color. They prefer to root for "gamers" like Eaton, Roark, etc. I get that. Underdog and all.