Suppose Congress is going to pass a law. They don't realize it, but it will devastate your industry by changing the rules midgame. Think about what Ubercab ("illegal cab") or AirBnb ("illegal hotel") recently went through.

Now, imagine that you can't sound the alarm. This is going to put people out of work and ruin your business, but you can't say anything.

That's what it means to prohibit lobbying.

To stop lobbying, you need to stop Congressmen from getting power-drunk and passing random rules and regulations that affect the economy based on something they just read in the New York Times (like the recent debit/credit thing). Companies generally don't want to lobby, they just do it as a defensive measure.