Why did they deflesh intact bodies unnecessarily?

Watching again and realised there are a couple of times when either a whole body or part of one has the bones "cleaned" for Brennan even though they're fresh, intact bodies.

Trent Macnamara's hand comes to mind but most notably Sweets. He was completely defleshed despite not being decomposed at all. Why on earth would they do that? It seems very morbid (more so than the show usually is) to deliberately strip him of his face and reduce him to bones like that.

Rubs me the wrong way a bit that they did that to Sweets.