I completely see your point - given the tragedy that overwhelmed Dutch football recently it seems hard to laugh at this.
But, on the other hand, Hazard's actions appear to me to be extremely foolish rather than particularly dangerous in intent. I could be wrong, of course, but I doubt he intended to beat the ballboy on live TV.
I can see the humor in it (and the ball boy knew exactly what he was doing, unlike the incident in the Netherlands where the linesman was simply doing his - unpaid- job) - but at the same time Hazard should not have resorted to kicking someone. He will certainly be punished for it.