Some people seem to have higher expectation for the Apple Watch. One of my co-workers used it for daily basic communication tasks, and complained that Apple Watch does support copying/pasting text which was annoyed to him.

I don’t think Apple Watch was meant to replace any other Apple devices such as iPhone, iPod, of Mac computer. Apple watch is customized to your personal activities like keeping track of your health, or your workout time, or send messages to the one your love. Therefore, I disagree with you that Apple watch is totally useless, but it was designed for a very different purpose.