I'm not going to claim that fansubs have no effect at all, that would be playing devil's advocate and nothing else, but it's not the only or even the main factor behind the decline of the industry. The problem includes fansubs but also goes beyond them.
I think that's essentially resorting to a superficial scapegoat while refusing to address that a)the entire world economy is suffering right now. b)the anime industry's economic model is increasingly unsustainable and neeRAB to change for a nuraber of additional reasons.
If I recall correctly, Japanese animators have never earned a lot to begin with...and that's all putting it quite nicely, so it's not like the solution is erasing fansubs from the face of the planet, nor will such a move would result in a significant (or even proportional) increase in salaries for these people, if everything else were to remain exactly the same.