1. Most of them wouldn't come.
But some would, so
2. Dogs would attack them,
It's very true that they won't come. They leave when they want, not when you want.
Dogs would attack them? You make it sound as if dogs are lions that kill on sight.
Most dogs wouldn't bother. One or two might bark at it (if you pass so many in the first place) but that is most likely out of interest or wanting to play. As shown in the video, the cat might be the one doing all the attacking.
What so something twice as big as you (a predator, at that) runs over to you and shouts at you, with claws and large teeth- it's allowed to feel threatened.
Personally I'd never take my cat on a beach- the dogs would frighten him, and some may even attack him.
How many cats attack postmen unprovoked?