Disagreement is encouraged here, Jeff. One of the core issues is that we can't agree as a society on what our education system should be, so we keep tinkering with it. If the desired outcome is better ability in a second language, then starting earlier is better according to the preponderance of research. Optional immersion is a problem too, because people opt in (based on parents' perceptions) and the system can push students out. If immersion for all was the norm, then we would support all students and teachers, as we do for English, Math, etc.

As you admit, there are not enough resources. Isn't that the way to ensure that a program fails - by not giving it adequate resources?

By making immersion optional, we say that second language abilities are not up to par with other, more important, subjects. In my experience, a second language is one of the few things that you can take with you into any endeavour. My ability to work in French has made the difference on several occasions on whether I get a contract or not.