That’s the beauty of the situation. Now, you are entering a new layer of strategy because the defending player will usually have more options at their disposal if they know the attacking player has to respect the fuzzy guard.
Edit: Forgot to reply to @inkstud
I don’t consider it to be an option select. I think an option select is where you give some input, then based on how the game processes the input, you can have multiple different outputs based on the current situation. For example, in Virtua Fighter, you could evade, throw escape, and then guard all in the time it takes for your character to sidestep (even inputting multiple throw escapes). Based on the situation, you would either escape a throw, side-step and guard a straight attack, or just sidestep and end up in the guard animation. All that depends on which three of these outcomes happen is what actions the opponent takes. The game automatically chooses between which of the three outcomes would apply. The important point here is that the options that the opponent takes could all land in the exact same frame. You would still be able to guard against all of those options doing this.
In the case of fuzzy guarding, you are defending against two (or more) options, but you cannot defending against each of those options in the same frame. That’s the important difference. To defeat a fuzzy guard, you can always delay one of your options so that both options land in the same frame. That’s why it’s a “fuzzy” guard. The fuzziness is the delay between the two options the opponent can take.