Especially with the first Tron where Clu is just a sort of throw away program of Flynn’s. Flynn likes Tron more, he believes Allan’s program is better than his own and Clu knows it. So when Clu finally takes over the Grid and essentially traps Flynn within the Grid it’s still not good enough. Clu STILL isn’t good enough. Flynn is STILL trying to find and reconnect with Allan’s program, Tron.