Catholics are no different. When they decide to accept the RCC interpretation of Scripture, they are accepting it as their own. Their own personal interpretation happens to agree with the RCC when they accept the RCC one.
But either way, it is still an individual choice to accept a personal interpretation of Scripture. Just because any one Catholics happens to agree with any other one Catholics is irrelevant.
EVERY person's decision is a personal interpretation of Scripture. It just matters whose it is, whether it's the *church's* or your own.
Or the decision to follow Christ through His Church over following oneself.