It is always based on predicted value. Why would you invest in something when you know it is going down? If you know MS is going down in the next 10 years, why bother to buy/keep it?
Well, actually I invested something for at least 10 years, so yeah, some people would still consider the investment. My current investment is looking at 30 years of local mimima and local maxima. But obviously most people have much shorter window for this.
Your Buffett is analogy is more suitable. It is your choice to see celebrity Justin Bieber concert with bunch of screaming teenagers. Or you can choose to attend an orcastra with less comfortable, more serious attire.
What people are annoying is, they went to Justin Bieber's concert and then, few months later, they bad mouth how fast he lost fame, and complain his concert ticket was overpriced. Such shallow loyalty.