How could one not have "false" alarms when the magnitude of the tsunami cannot be accurately predicted? So much depends on the amount of water initially displaced, how the waves converge across a distance, and the geography of each individual location where the tsunami reaches land. The best thing is still to warn people to get above sea level and hope the tsunami is wimpy like this one was. I can't imagine the officials passing on giving a warning (and I think it was only advisory and watch warnings on the West Coast) and hoping for the best. I had plenty of no-show tsunami warnings in Hawaii growing up, but I was always glad to have them nonetheless. As a kid, we all heard the stories about what happened in 1946. People today know what happened in 2004, or even last year in Samoa. And even if the tsunami is a wimpy surge like this, it still can create dangerous currents for beachgoers swimming in the water.
I think it's good for people to know that a tsunami is not necessarily a "big, scary surge"; people underestimate them too often because they look smaller and less threatening than the waves are expected to look. We can see in these videos that appearance of the tsunami varies a lot from location to location.
I like finding tsunami videos because these events are rare wonders of nature. I was a beachgoer for many years of my young life and I know what "normal" waves look like in various tides and places and so it is always interesting to see the water behave in unusual ways. That is partly what attracts people sometimes unfortunately to chase out the drawback and then get trapped by the rushing tide. And until the past decade, there were almost no videos of tsunamis available. Now there is a lot of documentation available.