The idea they had was to just make something up, like pandas and a series/columnar database, themselves. There are other competitors to kdb/q, but they are not as entrenched and maybe not a perfect fit. These guys cooked up a closer fit for their own systems, than, say clickhouse and other tools.

It had to be a very close fit to what they do, as kdb/q is pretty damned good at some things in finance. Maybe there is not enough money in the highly specialised areas it does very well at, for other people to come in with something new.

It would be a huge mistake to think sql is a replacement for Q.