Giving false assurance is exceedingly treacherous. People who give false assurance on whatever grounds pretend to be genuinely concerned, but wishes are not horses. A painted sword would soon defend a man, a painted house shall as soon shelter a man as a false hope would help anyone. That coworker is being naive and uncompassionate. This kind of talk is especially common with our loved ones who say things like "You're just being overly anxious about this non issue" "Nothing to worry about!" "It's a minor problem that will resolve itself" and on and on. This kinds of comment goes to show how men would habour a wish and then believe they have it. People think they can wish into existence whatever they want. If I think it then I can have it, and experience has shown that isn't true in most scenarios. That kind of comment is considered to be unkind, naive, and uncompassionate