Locarno covered up the accident that got a cadet under his command killed, and had other members of his squad do the same. He didn't come forward... he was forced to admit what happened. He didn't have remorse, he was only sorry he got caught. Plus, he was trying to shift the blame on Albert's death on Albert himself... definitely a lot of ego here, too. Especially considering he was in command, and if he knew one of his cadets possibly couldn't handle the maneuver, he shouldn't have tried to do it, never mind the fact it was banned already. He wanted to graduate in a blaze of glory.
Paris covered up an accident that got others killed. He did it on his own (as far as we know), but he came forward on his own and admitted his guilt. He had remorse, otherwise he likely would have gotten off with no one being the wiser.
Locarno: hubris. Paris: humility. The latter is definitely far more likeable and more redemptive than the former.
Well, all they did was tweak Locarno's backstory for Tom's so that Paris didn't look like a total asshole from the start, which made it easier to forgive him. In other words, they sugarcoated it. But to take someone who even the audience might think was completely irredeemable and turn him around...that's good writing. But obviously the UPN-hired writers weren't going to be tasked with going down that road. So they came up with a less offensive character that was easier to write for.