Inria is a public institution dedicated to research. There are many labs and people with separate goals. They are no more dedicated to ocaml than MIT is dedicated to emacs.

An even better comparison would be with, say, the NSF. I am sure that this or that technology has been developed by NSF-funded researchers, but it would be absurd to assume that NSF-funded researchers in MIT use and promote the same things as NSF-funded researchers in Caltech because they're both affiliated with the NSF.

I personally only know one team in our building here that uses Coq (written in OCaml) and all the rest use (depending on their field) C/C++ (robotics/ROS), Matlab, python (tensorflow/pytorch/sklearn,...)

Then again, it's not like I know the whole building, let alone the other parts of Inria ...

Inria is a public research institute. Researchers working there are responsible for so much more than OCaml, just citing programming languages on top of my head there are also Bigloo, Hop, Pharo, and Coq. There are probably others and there are of course many more projects that are not programming languages.

Well, Coq is written in OCaml after all, so my point applies here.

For those curious, here are the languages used in the projects

bigloo - written in C and scheme

hop - js and scheme

pharo - small talk and C

Coq - written in ocaml

It appears that Inria does not exclusively use ocaml for their projects.