Having notifications on your wrist is actually really great. Being able to decide if that buzz is important now or not is actually useful, and it absolutely isn't more detrimental to being with people and having conversations.
Perhaps you don't get your phone out for every buzz, but you probably do at least check it most of the time when someone is calling you. Seeing who it is on your wrist and deciding if it can wait is much faster, more seamless, and less of an intrusion.
It may not be worth as much as this costs, certainly for a lot of people, but it absolutely is a great feature. The Apple Watch is also far more powerful than the pebble, and it looks much better too (to be fair the steel pebbles don't look bad, the original though...). It will be interesting to see if there is ANOTHER killer app in addition to the notifications that the more power enables.