It is not a big concern considering the age of the vehicle. Sure, it would be better if it was rust free. To repair it would be expensive and probably not worth the expense. For me personally, I would look for one with less rust. My 2008 barely had any frame rust when I sold it.
Junker parts from non rust areas could help you out but it is still a good amount of money and work. Given what the rear subframe looks like I would make sure there isn't obvious rust in the bottom of the rocker and doors. If there is significant body rust run away from the vehicle. If body stuff isn't too bad and the price is right AND you are willing to tackle the subframe then it could work.
I would double check the body / take your time looking it over. . .
Keep in mind that at 132K it should have had its timing belt and tensioners, water pump, coolant, serpentine belt and spark plugs replaced. Valves should be adjusted too and go ahead and read up on SMOD on this forum; the radiator should be replaced to avoid it. . .
Here's a link to a rear subframe on Ebay that might be food for thought . . .Good Luck!
RIDGELINE 06-14 Rear. - The third level quality part. - The second level quality part. It is of average miles and normal condition for its age. - The highest quality part. It is of low miles and/or exceptional condition for its age.
PS: In your picture, the object in front of the subframe is the rear differential. It gets its fluid changed about every 30k miles. The drain plug at the bottom doesn't appear to have been touched in a long time. . .