I ride BART regularly. It's not fair to compare it with the Subte because BART is a regional transportation system - the suburban trains to Buenos Aires province would be a fairer comparison in which BART is light years ahead. And, while BART has infrequent if sometimes contentious strikes, its employees don't sabotage the system.
Then why did you bring up BART?
You should have brought up SFMUNI, which is "almost" as disfunctional as the Subte.