If you are interested in HMRC getting more tax with which to do things, why do you expect this new legislation to generate that?
There are several avenues that contractors can go down as a result of this recent fiasco, and almost all of them end up with the taxman getting less money (as well as the contractor).
Unless this is about putting the boot in to contractors (in which case, it's a job well done) ir35 simply doesn't generate more tax.