from your explanation it means the rule is self contradicting and should be looked into for a rephrase. Because if its not illegal to own multiple accounts then banning all multiple accounts linked to a faulty user should be put in view. The rule can be rephrased to say one account to one user and owning multiple accounts at owners risk. Otherwise this rule is just self contradicting and should be open for review.
It is not the rule that is contradictory, but your understanding of the rule. The rule doesn't prohibit having multiple accounts; it prohibits using them when one is banned.
Ban evasion ( using or creating accounts while one of your account is banned) is not allowed.
What part of this rule is unclear to you? To clarify, YES, you are permitted to have more than one account on the platform. However, NO, you are not allowed to use them if one or more of your accounts are banned.