Not surprised at all. The economy of football in Argentina is not what it used to be. The economy of the country is fuk and the big clubs can not play that talent monopoly game anymore. Without the big money they can't group the best talent of the country, and the last 7 or 8 years we have seen this big parity among all the clubs. Right now all the big clubs have is their name to attract. And in a city like Buenos Aires, that have more first division teams than any other country in the world, that can only take you so far.
Argentina is a football first world country, it's rooted in the life of people since an early age. The first association a kid has is usually with their local neighborhood club, which in Buenos Aires it really breaks down by neighborhoods. So the players are naturally going to stay with the club that initially gave them a chance without the money incentive.
You should see the amount of Chilean and Brazilian tourists in Buenos Aires.
So for a team like "las gallinas" River Plate, while still with a huge base of talent, trying to put a successful campaign is a crap shoot. Sort of like trying to bet big market sports at Pinnacle and expecting to come out ahead, it can still happen but. Ineptitude from the players and directors to let things get out of control with the 3 years relegation system used there.
One really bad year from Boca next season and it can happen to them too.