Nothing, I perfectly agree.It means dancing Argentine Tango, using the body of AT steps, with AT technique, with AT hold (whichever variety you prefer) to (usually) vals music, hopefully with certain characteristics (more continual movement, more circular movement). Yes, you can take other sequences from your so-called "real waltzes" and merge them into AT; you can blend the two. So what? Vals, as it is understood in this forum, is AT danced to AT vals music, with vals styling. What is the hang-up with this?!
The same is for me.Shrug. Depends on the piece of music. Some is very tango-able, others are not. IMO, he crossed genres.
I think that libertango can be considered tango.
Althought its strong 3:3:2 rhythm can create difficulties to some dancers.