There is absolutely nothing that stops the industry from being dependent on it. It is a very real risk. But restricting immigration is certainly not the solution.

I've seen you argue for a market where demand doesn't meet supply as a desirable state for the labor market. If you do believe that, then there is really no basis for this particular debate. The principle of my argument has been that there is a problem, labor shortage which cannot be fixed by the solutions offered. If you're arguing that the labor shortage is not a problem, then that is a completely different debate.