The Classroom versus Online Learning of an Additional Language

The Internet is a fertile new space for the development of  effective and inexpensive learning solutions.

In order for this statement to have meaning, certain contextual dichotomies (not as discrete opposites but rather extremes that fall along a continuum) need to be addressed beforehand: (a) explicit/implicit learning, (b) native/non-native speaker, (c) instructed (formal)/naturalistic (informal) learning, (d) deductive/inductive inference, (e) concrete/abstract thinking, (f) declarative/procedural knowledge, (g) intentional/unintentional learning, etc.  Without considering these dichotomies, the risk is that some may interpret any use of technology as being fruitful.
It's been my experience that noticing, consciousness-raising, attention, etc. is best served through interaction (with human beings) which provides feedback, recasts, and positive/negative evidence back to the language learner.

The classroom, at great cost, reduces this spirit of independent learning and inquiry.

I guess this depends on who's teaching the class.  If we are talking affordances (i.e., potential for action), the classroom (with a teacher) offers more to motive students, provide strategies that lead to learners engaging in the language (in and outside the classroom), and help language learners notice differences between L1 and L2 in ways that better lead to intake (gasp).  I recognize that potentiality and reality are two different things, but the classroom can (and does in some cases) breakdown the barrier between formal and informal learning.  In other words, it's easier for formal learning environments (like schools) to incorporate informal learning than vice versa.

It will remain the job of the teacher (i.e., as didactic leader, facilitator, and coach) to play "curator" in orchestrating the learning ecosystem that evolves around the language learner.