I don't really like robotic voices, mainly because they talk too slow and I'd rather just read the text and get on with it. Then again, if I were to read it, I might as well go to a blog post. Unless you're using some kind of program that gives a real smooth voice, I wouldn't recommend it.
You can use it as an artistic instrument for example for reading a comment or quote to put am emphasis that it's actually not your opinion or to make it like a conversation.
As far as videos with only robotic voice go - absolutely no they are usually almost unwatchable (from the odd grammar on the few I saw some people in Asia do this and it might be their only option but it's still a bad one)