It could be a load bearing wall that is not set up to handle the plumbing. E.g., we had to fur (fir?) out the wall in my master bath because there was no code-compliant way to run the vanity plumbing in the load-bearing wall. The alternative would have been running the drain line outside the wall, but inside the vanity cabinets.

Couldn’t this line go under the house instead of wall?

I don't have a diagram of your plumbing, so I don't know. I live in an area where everyone is on a slab, so that option doesn't usually come up.

I have a crawl space it just seems odd

Was common in homes built 1960s.

I will admit, at some point someone did the SAME thing in my kitchen. We're undergoing a remodel in the next month and I'm hoping a plumber will be able to get rid of this and run it beneath the floor since the basement is right below with easy access. Idk how this could be useful. Seems like a LONG way for the drain to run since the wall is like 5 feet away from the sink. My home was built in 1917 so wondering if the age of the house has something to do with it. This is not a pretty sight to have.

I’m in the start of a remodel and we knew this would be issue but I’m hopeful it’s easy fix.

If you have enough floor space, you could use this opportunity to pull the cabinets out and have deeper counters on that wall. Water pipes would need to be extended though. Were the old cabinets built in place?

@the kitchen place.... Wow common for 1960s build. Do u think it’s and easy fix?

My previous house (built in 1946) had a similar situation when we remodeled. It had been plumbed that way during a previous remodel, where the sink was moved a few feet along an exterior wall that was masonry and had no cavities.

Blocked off corners, blind corners and Small 'barrel' shaped revolving lazy susans are what went in the corner cabinets back then. Talk to a plumber about cost of moving the drain if you choose to move it.

Thank you @kitchen place definitely going to having it put under the house. It’s the strangest thing.

@mama goose On the wall with the odd pipe is also the AC/Heating vent I think it would interfere with cabinets.