Why Are Investment Bank Bathrooms so Gross

They expect you to hold it in for 18 hours so you can keep working, so no one needs to use them.

I will attest to this. It's not that the bathroom is filthy, but that people don't clean after themselves - what I assume are genital hairs/pee droplets on the toilet seat or unflushed toilets. I assume the pee splatter is from people that pee standing up with the seat unraised on the toilet (rather than using wall urinals or whatever they are called).

Even heard juniors talking about them using the sink to pee before - which is crazy

Stress, terrible Seamless diets, caffeine/nicotine/adderall abuse

Depressed and angry analysts taking it out on the bathroom. Predictable

In my experience, it’s people being so hasty to get cranking on the model that they don’t take their time to clean things up properly.

Banks too greedy to pay a properly sized cleaning staff when it might cut into the bonus pool.

Goldman notoriously had a seedy building on broad st (before the current location).

To be fair most Trading floors are just long lines of desks and during intern season their are just destroyed folding chairs everywhere as the interns don't have a perm place to sit. People don't tend to care about the big spaces. We are a smaller shop and have dirtiness not only in the bathroom but the common areas.