As always there usually is a reason for a spotting. Alp are extremely shy and this is the reason of the rare spottings. So when a Alp is spitted it's usually not by chance. As any other animal they are territorial and if not seen it's because their territory is remote or isolated. There would have been lots of Alp spottings if this were not the case. Since the Alps live in forests it's disturbances in these environments that force the Alp out and being seen. One example of this disturbances is logging. Huge areas are cut down and this forces not only the Alp but other animals to seek new territories.
Look at the images below, this is what I talk about. This kind of disturbances effects all wild life and decreases the animals natural habits.