Just as a clarification, I don't use this loophole.
But I don't think that members should be banned over this. There are two paragraphs (main "Loans" page and "Select Assets" page) with stated rules, both conflicting each other. It should not be a player's responsibility to decide which set of rules to follow. And if the system prefers the latter (the "loophole" rules) set of rules, then they player should be able to use the latter set of rules.
It could be that Sami intended for the former set of rules to be used, and the second set of rules was a forgotten remainder from previous games. But as a native speaker of English, I can tell you that the way the passages are worded, both rules are equally as strong as each other.
Modify the game (like JumboShrimp said) to have an 80%-100% cap on loans. Then delete the passage from "select assets". I think that would solve the problem.
Just my $0.02 .
EDIT: Oh, and people have been (ab)using this for ages. How do HUGE carriers become so huge, when everybody else is stuck with mediocrity? I have to say that at least 10-15 people each game actively pursue this strategy.