You know why they're shielded? BECAUSE IT WAS AN INCENTIVE TO TAKE LESS MONEY IN SALARY!!!
Everyone who is honest with themselves knows that college-educated teachers make less money than they could if they worked in the private sector. Why, then, do teachers (and cops and firefighters and all other public workers) take the job? Partially, because it's something they really want to do, and they're willing to earn less to do it.
But another motivation is that they base their compensation on future earnings. They take less up front for the stability of knowing that a modest pension is coming on the back end.
These pension "reform" maniacs are trying to mess with this explicit contract so they can get the short-term benefit of screwing current and soon-to-be retirees out of their contractually due compensation. And there's a good chance they'll find enough morally and intellectually bankrupt judges to let them get away with it.
The problem, however, is that they are taking pensions off of the table now and forever for those entering the workforce. When young people see that pensions were what Mary Poppins called a "pie crust promise" - "easily made, easily broken" - they simply won't accept them. They are going to want to see the scratch up front.
And the taxpayer will have a choice: pay up, or accept a lower quality of worker.
The pension maniacs are playing an incredibly dangerous game; it will have consequences long after they've moved on to the next life. Are we so short-sighted that we can't see this?