I think we have been talking about trends in here. Volleyball is pretty new to Turkey which started to become big around 2003 and now Turkey has a good female team that can compete in top tournaments. Developing players like that in 10 years is a big success IMO. About the teen issue - which team has key players in their teens? Kosheleva in Russia?! Kubra Akman in Turkey is a very good example to that. She is 19 yo, is the best blocker of the tournament now and led her team great. I believe Turkish federation is doing a good job by investing on such young players and there will be many more coming soon. Btw maybe it does not count but Turkey won't European League this summer with a very young team as well.
Coming to other sports. In Turkey Volleyball is the 3rd biggest sport after football and basketball. So it is not different than other countries. Investments to football in Turkey is crazy but there is no success at all. So actually very recently I read some news that more sponsors are getting interested in volleyball than football since volleyball teams are successful. Again that was a very good strategy by the Federation and the clubs.
Finally if you think that it is not hard to organize a top league, why don't others do that? Maybe sponsors/ funders don't see them attractive enough to invest?
How can you say Turkish league is big and successful because of Italy's financial problems? I still love Italian league and I am sure if they had the money the league will still be on the top, BUT Turkey has been making big investments in volleyball for over a decade now. It's not a success over night as you mentioned in Azerbaijan. Turkish league has been growing year by year and there had always been some great players playing there. Also you can look at the Junior and Youth competitions Turkey together with Serbia are one of the most successful teams so it tells you how much they invest in young players too..
And I am not Turkish....