I'm not surprised in the slightest. Caltech has a reputation as one of the best research universities in the world and getting a degree or doing research there requires a lot of work because it's so competitive. I've spent many nights as a kid running around Caltech in the dark while my mother worked on her experiments till midnight or later (all of the turtles come out at night!). Publish or perish goes tenfold for the elite schools which have a never ending supply of talented postdocs.
Though I'm not surprised that this letter came from someone in the chemistry department. ChemE especially has a reputation within Caltech as one of the most difficult paths for both undergraduate and graduate work. The ChemE specific classes usually require a much bigger time commitment and the tests are notoriously difficult.
I used to be in a long-term relationship with a chem undergrad at Caltech. I saw her all-nighters and stress first-hand. The workload drove her to attempted suicide (and had she gone through with it, hardly would've been the first suicide at Caltech).
We split up and it took years for both of us to recover.
I went to one of the greatest grad schools in the world- UCSF- and while there were lots of people who worked absurd hours, I can't say I found it was necessary. Some people in academia just overwork without it leading to greater productivity.
I don't mind once in a while having to start growing cells in the morning and hanging around for until evening to collect the results. The expectation that you should always be working that kind of hours... well, it doesn't make any sense to me.
The one that really bothered me is that some of the professors would come in on Saturday morning and call their students. It wasn't that they needed them. They were just bored and lonely.
Though I'm not surprised that this letter came from someone in the chemistry department. ChemE especially has a reputation within Caltech as one of the most difficult paths for both undergraduate and graduate work. The ChemE specific classes usually require a much bigger time commitment and the tests are notoriously difficult.