It is a plot hole. What Rtas says, which I quoted, is baseless, for he implies (and you outright state above) that the bond can be broken just because Kreia wants it to be broken - this allegation is contrary to what we learn about it from the first time it's spoken (that it was formed by accident, that it's dangerous, and that they can't get rid of it as far as they know).
To say that the game does not explain it clearly is putting it mildly. The bond is never even mentioned in the game past Telos (that is, Telos after the Jedi are killed on Dantooine), and even then only if the Exile kills Atris, prompting Kreia to contact her and tell her that she has to go to Malachor (since Atris, being dead, can't tell her). What everything about the Force bond that we are told in the actual game adds up to is "If one dies, so does the other." The only part of the game which even suggested that there is a way to get rid of it is the conversation with Vash on M4-78 (or wherever the hell you were supposed to encounter her), and even then, it's hardly comprehensive and leads to plenty of other unanswered questions (IIRC she says that if one turns to the dark side, a bond gets weakened/broken/whatever. But if that's the case, what happens if both members of a bond turn to the dark side at the same time, or if both are dark-sided at the beginning and one starts to drift to the light? And how does this make sense if we consider the fact that Kreia was attuned to the dark side from the beginning?). And, of course, the whole thing got cut from the game anyway.
Thus, during the final conversation at Malachor, neither the Exile nor Kreia even mention the bond (not even in cut dialogue, as far as I've heard, which makes me wonder whether the writers ever even thought of what would actually happen in the ending). The Exile's survival (which technically we don't even see if we go by the light-sided version, only the Ebon Hawk appearing nearby and then flying off) goes without explanation in relation to the Force bond, which is a major aspect of the plot from the beginning of the game. Plot hole.
"Grant Allen [...] had written a book about the Evolution of the Idea of God. [...] it would be much more interesting if God wrote a book about the evolution of the idea of Grant Allen." ~ G. K. Chesterton, The Everlasting Man