Newsflash: a two-word category descriptor isn't good at conveying nuance. It does pretty effectively convey the idea, though, that in whatever specific area of application, storing and processing data is a core technical challenge.
If you need a shorthand "way to describe startups that are dealing with large quantities of data", as a non-nuanced category, "big data" does a pretty great job.
If you need a shorthand "way to describe startups that are dealing with large quantities of data", as a non-nuanced category, "big data" does a pretty great job.