I was optimistic when Facebook first came out, and it turned into a dystopian nightmare. I was optimistic when self checkouts appeared, and now I feel like I'm a criminal by default every time I get groceries. I was optimistic about more people being online, and now we all feel like we can't get off it. I've become increasingly cynical about tech because of these and a thousand other disappointments about the utopia that was promised turning into not much more than an efficient means of extracting money from all of us.
I don't think it's ever a good idea to be totally optimistic or pessimistic about a new technology, because then we're liable to ignore anything that goes against our narrative. Really, we don't know, and we can't know what's best for ourselves, usually until it's too late.