Julia's DF library is generic and allows user defined ops and types. You can put in GPU vectors, distributed vectors, custom number types etc. Julia optimizes all this stuff.
data.frame is just a giant chunk of c (c++) code that one must interact with in very specific ways
These features aren't of interest to practicing statisticians, which the parent comment was talking about.
> data.frame is just a giant chunk of c (c++) code that one must interact with in very specific ways
I don't understand this criticism: yes, data.table has an API.
It's pretty convenient for things like uncertainty propagation and data cleaning...all things statisticians should care about.
>I don't understand this criticism: yes, data.table has an API
A relatively limited API, walled off from the rest of the language.