In this life, Tom Riddle was not Lord Voldemort, and he never would be. That did not mean that Tom didn’t share more than a few traits with the evil Dark Lord he’d almost become – namely, a burning desire to punish those who wronged him. But Tom, unlike Voldemort, had one person he very much wanted to keep close and happy, and when that person asked Tom to spare his muggle relatives Tom paused. He weighed his need to punish the Riddles against his need to keep Harry by his side and the latter won easily.