Here is another way to formulate my question:
Given the amount of time it takes for gains to show up, does CI work? (This means that if we have 400 hours in a four year program, which is a top realistic quantity of actual hours of CI available to us, and we need somewhere between 10,000 and 24,000 (for Chinese) hours to get to real command of a language via CI instruction in a school classroom – which is a very different setting from the one Dr. Krashen did his research on – are the gains that our students show in those 400 hours enough to show that CI “works” to those masses of language educators, administrator, parents and students who don’t really get what we do?)