It is my understanding that ruthless, backstabbing things like that happened much more in the past. As time has gone on, ballet dancers have become more civil and amiable toward each other - though there still can be a lot of competitive tension. Dancers are just a lot "nicer" about wanting to beat out their colleagues for roles/positions these days. The ample competitiveness that exists among dancers is often concealed with a veneer of (reserved) friendliness.
When I watched the early episodes of this show, the "cattiness" the dancers exhibited toward one another immediately struck me as exaggerated and somewhat unrealistic. This was part of the entertainment value - knowing that dancers generally don't behave anywhere near that ridiculously toward each other these days.
Don't get me wrong; things are likely not always very "warm and fuzzy" among dancers (who all are vying for a very limited number of soloist and principal positions) - and I'm sure that there are a lot of relationships that are compromised or non-existent. But for anyone who walks into the headquarters of a ballet company expecting to see and hear the things that were in "Flesh and Bone", they mostly would be disappointed.