The standard slam against Protestants is that we have so many denominations. You have Catholic apologists who inveigh against "ecclesiastical consumerism" or even "ecclesiastical promiscuity".
That's set in invidious contrast to the notion that Christ established a single visible church–which just so happens to correspond to the church of Rome.
But let's consider a basic problem with that alternative. If you think there is only one church, which happens to be your particular denomination (e.g. Rome), then that commits you in advance to defending that institution no matter what. You are struck with that denomination regardless of what it's leaders say and do. You swear it your unconditional fealty. You become soldiers for your denomination. You will stick up for your denomination no matter what actually goes on in your denomination. If there's only one true church, then it's that or nothing. Rome or bust.
Yes, you may offer throwaway concessions about wrongdoing, but that can never lead to you to question your totalitarian allegiance to your particular denomination. It can never become too bad for you to walk away. It can never become too evil for you to stop defending it. It's classic fanaticism: my church right or wrong. That's because they have no fallback.
We see this in how Catholic apologists respond to the never-ending stream of new revelations about the priestly abuse scandal. Or how they constantly make excuses for Pope Francis. They will not allow anything to shake their faith in Rome. If the pope performed a weekly child sacrifice at St. Peter's basilica, they'd assure you that does nothing to discredit the institution.
Catholic apologists have no moral independence. It's like a stark version of divine command theory. Good and evil are whatever Rome says. There's no external check. Rome itself is the standard of comparison. Catholic apologists have trapped themselves in the unbreakable circle of cultic authority. You can never leave the cult, for the cult-leader defines what is right and wrong.