I AM a physician, and yes, whoever does the demonstration takes quite a bit away from the demonstration by being pretty horrific at suturing... like 2nd year medical student who hasn't practiced bad. If they are going to compare quality of tissue approximation between sutures and their glue, they should probably use proper technique. A plastic surgeon would have laid out 10 sutures or more into the same space, probably in half the time. I am sure there's a senior surgery resident out there who wouldn't mind getting a few hundred bucks to tie a few sutures on camera.
That being said, there are some structures in the body that are very fragile, and difficult to sew. Also, the elderly and the chronically ill have tissues that just fall apart, limiting the usefulness of many surgeries in managing their illness. If we could create seams that don't rely as much on tissue strength, we could probably operate on quite a few more people.