From what I have seen on urine therapy they are trying to get whatever the body had excess of that was being excreted in the urine such as hormones, vitamins, minerals, etc.
There is a lot of stuff we could use excreted in the urine. For example all the excess vitamins we consume and minerals being excreted. But I would rather get these from some great tasting food like pizza or a burrito. I don't care to drink my meals :-)
My biggest concern though is the re-ingestion of ammonia compounds that the body was trying to get rid of in the first place. It also defies logic in my mind to re-ingest something that the body had the sense to get rid of in the first place.