Party and event photography

Just recently I was at an event and saw an event photographer at work. Full lighting rig. And as guests came in he got them to stand in a pose and took a formal shot. Now I am sure in that style what he did was excellent.
For me it was a shame. The guests were very lively and there were so many wonderful opportunities to get very human candid shots.
A picture that shows a slice of their live from one moment in time at that party. A picture that would jog their memory of the fun they had on that particular evening. A memory to treasure.