It looks to me like the shooter rod on the right side is also slightly off center (so there is room for the whole playfield to shift to the right).
I know you say the left hook is straight, but it doesn't look like it to me from your picture. Maybe the angle of the picture is misleading. Even a tiny amount of crookedness could make a difference.
You could tell if the entire playfield is crooked by either measuring or eyeballing the distance between the siderail and the inside wall of the cabinet on each side...looks like it you could have a larger gap on the right compared to the left).
I agree that it doesn't make sense for the left to be that off, but it would take about 2 minutes to loosen the four screws that hold the hooks, and then see if you can shift it into a better spot.
You can also loosen the black metal covers on each side and adjust those.
If you think the playfield is "wrong", then you could measure the distance between the slits in the shooter lane where the switches sit, and then measure from center to center (which might be difficult) of the shooter rod housings. I would guess those measurements should be the roughly the same.