An athlete always wants to compete, it is impossible to achieve anything in sports, if you are not ok with spending at least 20 years of your life in said. I don´t know of any athlete who did it for the money or for fame, it is just a side effect of your career. This I think is the big difference to normal jobs, that someone picks up in the mid 20´s after university. You might invest 10k and three years, but after that you are settled and can survive.
Before an athlete can make money, however, he or she (parents) has to invest 10 years and thousand, at times hundreds of thousands $$$. Nobody would do this if he or she isn´t passionate about it.
Therefore, an athlete of course want´s to have a long career, as this is what they have worked for all their life. Adelina, Yulia and Liza all had health problems after they peaked and won titles, without those all three would have won much more. Adelina even once noted how skating for her was also a way to give something back to her family and especially her sister.
I would also say that none of them has just "faded away". Yulia kept skating if she was healthy, Liza won a few medals as well and always helped other skaters of the team - they are far from medal taken and goodbye. Adelina I think, was just completely overwhelmed by everything, but I have not met her since the Olympic season, so I am not sure exactly, if it was just the injury that kept her away or maybe some other stuff too. Keep in mind, that she received a huge amount of harassment after her victory, this can break a ladies heart easily and maybe this was all just too much. My latest news about her is being with Plushy since April this year, so as you can see, she is still there, trying to come back just like all the others.
That being said, there are certain aspects that can change your approach to the sport, as we saw with some of the American champions in the past. Sarah Hughes and Tara Lipinski, who took the gold and left immediately. Of course, both also had injury problems, Tara I believe hip and Sarah back. In Tara´s case, there was also a change in the industry as people lost interest in the sport, events got cancelled or turned into "minor ones", so she might not felt that motivated anymore, or it was just too expensive, I don't know.
Last but not least,
I strongly disagree that Radionova and Pogorilaya did not achieve much. We are talking of two skaters that have medaled at the GP and at Worlds, Europeans, Nationals and international competitions. Put this into perspective to thousands of athletes that don´t even qualify for any of those events. These are huge achievements, to belong to the top three in the world, nothing we should just call "without great accomplishments".
Her 3F is much better. And with a single lutz she may feel herself more confident. 2 points handicap - it's not so big. Nastya could fight for a win. If she'll be clean of course. 
