No matter how important Lin Yi's existence was to him, if he was forced to use his veto right at a time like this, he'd lose face as a top-tier Big Shot, and it'd make the other big shots very unhappy.
The one-vote veto was indeed the privilege of the top Giants, and there was no dispute about this.
However, the problem was that every time he used the one-vote veto, it was essentially consuming the authority of the top big shots. Once this authority was consumed too much, the credibility of the one-vote veto would also be reduced.
If Gu jiumu was forced to use his veto power to protect Lin Yi, he might not even succeed, and even if he did, it would be a huge blow to his reputation in the eyes of the other big shots.
Perhaps the next time he used the one-vote veto, it might not be as effective.
As such, unless it was absolutely necessary, Gu jiumu would not use his veto power.