Perché questi Azerbaijanis parlano solo russo?

Some clarification:

First please dont pay attention to the inflammatory title of the video, I guess it’s just to get clicks, it’s actually in the end a really nice video about Azerbaijan.

They start off in Baku and meet some guys, they’re Azerbaijanis but [they’re all speaking Russian](https://youtu.be/7w2MlJLi7us?t=788) and they speak Russian [throughout the video](https://youtu.be/7w2MlJLi7us?t=1747)

It also looks like originally these guys are from Quba, not from Baku originally. But later they go to Quba and the locals there are speaking Azerbaijani.

Is Russian usually people’s preferred/first language?

At home do you speak Azerbaijani or Russian?

Thanks <3