I have to use it at work, helping quants try to actually maintain production code rather than just vomit horrible one-time scripts they patch together in an endless stream of layers on top of layers.

This thing should be banned. Everything is one-letter, it's impossible to Google, it takes the opposite decision of every imaginable convention, I have yet to see someone who can read his own stuff 2 weeks later. Notwithstanding free tools to query force-expire every 3 months (QPad grrr) and as you said it's so closed they have to take webdevs like me to just help them maintain it all eventually.

It's risky for the bank (and we're not a small one :s), it's expensive for the programmer, and it's misery for the quants (but they all feel like geniuses spending weeks on simple stuff on kdb, so their misery is only in people looking at them wasting away their brain like that).