> most modern psychology seems to be, well, kind of bullshit
Based on what? What better source do we have that contradicts it?
Identifying, defining, and measuring psychological phenomena is much more difficult than doing the same with physical phenomena, for obvious reasons. That leads to lower accuracy. Should humanity not even try, leave these questions unanswered, and suffer the consequences?
While there are many failures and there are the flaws associated with every human endeavor (and that applies to other fields too - computer security comes to mind), modern psychology successfully treats many conditions and helps a very large number of people. Consider the world before it, when we didn't understand depression ('stop being lazy!' 'just buck up!'), schizophrenia (demonic possession), bi-polar disorder, anxiety, PTSD (General Patton assaulting a hospitalized soldier), etc. Is all that knowledge and treatment just "bullshit"?
It's sort of common on HN to toss off derisive remarks about psychology - or any field besides what HN readers personally know well, such as computers, math, and natural sciences - but let's hold ourselves to a higher standard: What do we really know?