Remember what Laguna said after Adel defeat that he said use strong emotions (love and strong bonds) to achieve TC but Squall didn't do what Laguna said, all what Squall did was blaming himself that's why Squall didn't achieve TC and ended up on a stone land, his OP affected by Squall.. that explains why they all didn't achieve TC too. However, Rinoa wasn't affected by Squall, because Rinoa is on the other side (Ulteimca) and she came to wake Squall to end the TC.

This assumption makes sense for me, I guess.