This is a pretty hostile forum and I'm sorry that people have responded in such a typically glib and inconsiderate manner, but I guess that's the internet. (FWIW, you do come across as defensive in your later posts, but I can't blame you. The whole tone of the thread soured very quickly. I think maybe people didn't appreciate your use of the would "should" rather than 'could.' I'm sure it wouldn't blow your mind to hear that some people are very sensitive to potential criticism of something they enjoy.)
It's always good to look forward but I do think what you suggest poses some design obstacles. In terms of eventually having just one device and it being wearable, I think you are right. But I don't think it will be a watch. A watch is a one-handed device that requires an arm position that isn't very conductive to long periods of use. I think it would be a limiting platform to try to do absolutely everything. Besides, once we've got neural interfaces, why bother?