I've been in and around the New York Tango scene for a long time. When beginners want to start out right ? I send them to Dance Manhattan. And when more experienced dancers are looking for interesting workshops with visiting instructors, private lessons, etc. I also point them toward Dance Manhattan.
The Argentine Tango is not an easy dance, I think people get frustrated and blame the teacher or school when they have simply not given themselves enough time to feel comfortable at a Milonga.