Harper's injury wasn't that serious, and he has come back from every injury with little or no rehab stint (I think in 2022 he did like three games - and then stunk for a month as well). Remember, he has a chronic back injury as well, that isn't going to go away, and who knows how his elbow feels after throwing every day for the first time in two seasons. All just part of being a baseball player. He does not need a fake/illegal trip to the IL, or to be benched, and I don't think it's a character flaw either. Just a slump that's even harder to take right now since it's the whole team (and he's the only one who can carry the team).
I still say it was a huge mistake to take the pitchers who weren't pitching to London (and to pitch Ranger at all there), and it was probably not ideal for Harper to play in the All-Star game after he rushed back from his injury. But that's his prerogative.
Over the first two months the offense was great but the pitching was even better. Now, no Turnbull, Sanchez can't win on the road, no Suarez, Wheeler was injured, Alvarado bumpy. It's a little bit of everything. It is less than ideal that a long West Coast road trip is the place where they need to get right though we've certainly heard "maybe getting away from the pressure at home can help" in the past.