That said, we may have to get a little creative to support some specific use cases (e.g., bitemporal modeling). Still TBD.
Also, I agree that SQL isn't for everyone (the popularity of PromQL is evidence to that). But a lot of people have been using SQL for a while (personally, since 1999), and there is a rich ecosystem (clients, tools, visualization tools, etc) built around it.
And temporal and bitemporal databases (despite the name) are orthogonal to the aggregation and windowing issues that make time series difficult in SQL or a row-oriented database. The are just a couple of timestamps and where clauses to support point-in-time queries.
Maybe this is why so many time series databases fail. People making them often don't seem to fundamentally understand the issues, Very few, such as Kx and KDB, seem to understand them.
Maybe Postgres needs pluggable storage engines [0].
I read Postgres 10 might have this, but looks like it will miss the deadline.
[0] https://www.pgcon.org/2016/schedule/events/920.en.html