Try watching it without US commentators blowing smoke up one guy's backside. Watch the international feed (ironically, which also featured US commentary but they were more focused on calling the action than blowing smoke), keep an open mind & learn the answer to your own question.
It wasn't a robbery because it was a close back and forth fight round after round, highly competitive, difficult to score. The commentators throughout the match kept saying how hard it was to score, how many close rounds there were, etc. Haney was the Undisputed Champion. Loma gave a good account of himself, and deserves credit for his performance, many fans in the past have argued that to dethrone the Champion, the challenger needs to leave no doubt over who won. Even Loma afterwords in the post fight press conference alluded to that, he said maybe he didn't make it clear enough that he won.
I think if you want to argue that it is not reasonable to score the second, fourth, fifth, sixth and twelfth to Haney, I think you've got that wrong. That's five rounds. No reasonable person should ever give Haney the 3rd, 10th or 11th. That's eight rounds. So there are four rounds remaining that were close, and difficult to score. I don't accept there is no way a reasonable person could score one of those rounds to Haney. So that's my answer as to why it's not a robbery. It's possible to find a very reasonable scorecard that has Loma winning just six rounds based upon tv pictures.
You can't give Haney 7 rounds without giving him close but clear Loma rounds. To give Haney more than 3 rounds you have to change historical boxing scoring by equating body shots with head shots. If you converted this fight to faceless boxers and gave it to 100 boxing experts you would be lucky to get a handful scoring for Haney. People keep talking about "swing" rounds. What makes it a "swing" round? Were there an equal number of punches from both fighters? Were both fighters equally aggressive? A round has a winner. That is the rules of the must system. The only way to score this for Haney is by making every single sequential 50/50 decision in his favour. Statistically highly unlikely, which is why we know this is corruption. The Haney fans scoring in his favour are just dishonest. Can I also remind everyone that the media will never call corruption. To do so would be destroying their livelihood. Therefore they have to all tow the line and say in some universe Haney won the fight.
If by close but clear Loma rounds, you are referring to rounds 1, 7, 8 and 9, according to Compubox : Round 1 : Haney 6/32, Loma 6/26 Round 7 : Haney 9/33, Loma 11/50 Round 8 : Haney 9/34, Loma 9/47 Round 9 : Haney 13/39, Loma 9/48 Totals for these rounds : Haney 37/138 27.81%, Loma 35/171 20.47% According to Compubox, they landed the same amount of punches in Round 1, and Haney landed 2 more punches in rounds 7-9. Now we don't score rounds by Compubox, and Compubox often is misleading, however the data indicates that those are each very close rounds. That's not true. All you need to do is to split those 4 rounds, i.e. score 2 of those 4 rounds to Haney and 2 of those 4 to Loma and you end up with 7-5 Haney.