The situation in BA is a bit different because unlike in most of the rest of the world properties here are not bought as an investment but as a way to protect yourself against economic turmoil, devaluations, etc
Because of this a typical homeowner owns many properties and does not care about the ROI, they won't even do the necessary maintance, etc. That's why there are so many sub-par properties on the rental market.
This eventually will backfire, the foreign arrivals so far this year are about 20% down, many Argentinian students from the interior are not studying in BA. Within a year or maybe 2 Argentina will be back to a situation in most of the 90's where many properties were empty. In my opinion it will be like in the south of Spain where you can be very lucky if you can rent out your property 2 or 3 months a year. And with the constant price increases they are going to suffer.
Right now the temporary rental market has an occuptation rate of about 30 to 40% and this have to go down.