Yes, they should be doing far more, to establish other industries. Unfortunately, the States of Jersey normally takes the too little, too late route in just about everything.
But, you can't blame them for this LVCR industry, it was all started by private individuals, who were always operating within the law, and taking advantage of a law which was not under Jersey's control.
The fact is that all countries use taxation to encourage, or discourage certain activities. For example, the UK provides tax credits to the movie industry.
I don't believe that LVCR is/was anywhere near as damaging as its critics would claim. The money UK shoppers saved on DVDs, etc. they would have simply spent elsewhere within the UK economy.