> forcing Congress to do its job

> Why are they dreading this?

You answered your own question there. Congress should do its job, but as a matter of fact it is not doing its job and it is not going to do its job anytime soon.

The Court might be technically, legally, philosophically correct in removing the inelegant hacks that the previous courts set up to route around the fact that Congress does not do its job. But in the meantime, Congress is still not doing its job.