There are some things that are broken about Fed civil service, however the GOP big thinkers mostly don't understand what they are or how it actually works and are more likely to **** it up worse than they are to fix it.
Two of their biggest misconceptions, which you can gather from listening to Fox Business shows like Steve Forbes and his gang of dipping birds, are:
"Those unions must be put in their place" - Federal unions can't strike and can't bargain for pay and benefits, those are set by statute. They may technically cover a big percentage of civil service workers, but only a tiny handful actually pay dues to them. Unlike State employees, where wages and benefits can usually be bargained, unions are a toothless artifact of bygone days in Federal civil service. They can grieve stuff, sure...BFD. The grievance process is insignificant next to the thing that stands in the way of firing people quickly is all the free hearings and layers of free 'Due process' CONGRESS provides via the MSPB, EEOC, and OSC, not the unions.
"Lavish defined benefit pensions" - that stopped over 25 years ago, the current system provides a limited defined benefit (1% of annual salary per year of service, i.e. after 30 years you get 30% in pension and get to keep your health insurance as long as you keep paying for it out of that, until they convert you to Medicare at 65) plus the opportunity to participate in a very generic, inflexible crippled 401k-like program, heavily weighted to (What else) US government securities, with the most aggressive possible option being an S&P index fund. The gov does pitch in an extra 5% of your salary on a sliding scale up to the first 5% you put in, and you can put in a max of 10%. It's okay, it's not fat city.
The Dems at least understand enough about it to know that the GOP brain trust doesn't understand the way it actually works, and they're inclined to just leave it alone, which is really smarter than fixing the wrong stuff and then looking stupid when it doesn't work.