Bunch of reasons, many have already been mentioned here. Another thing to consider is that the barrier of entry in the UFC and other high-level MMA promotions is very low. For example, Cody Garbrandt got into the UFC with only five pro fights, and lots of guys come in with similar records. If it were harder to break into the major leagues, I'm sure more MMA fighters would pad their records.
Something else is that there are a lot more ways to lose in MMA, so it's not that easy to just pad your record coming up. A fighter might be really talented with a ton of potential, but he/she could run into an opponent on the come-up who they weren't ready for. Tons of great fighters have losses early in their career for just this reason, and many of the guys they've lost to are people none of us have heard of.
As for O'Malley's case, he's clearly taking these fights to troll the UFC. He's said as much in interviews. It's not gonna last much longer, though; Dana's recent comment suggests that the UFC's patience is wearing thin.
Something else is that there are a lot more ways to lose in MMA, so it's not that easy to just pad your record coming up. A fighter might be really talented with a ton of potential, but he/she could run into an opponent on the come-up who they weren't ready for. Tons of great fighters have losses early in their career for just this reason, and many of the guys they've lost to are people none of us have heard of.
As for O'Malley's case, he's clearly taking these fights to troll the UFC. He's said as much in interviews. It's not gonna last much longer, though; Dana's recent comment suggests that the UFC's patience is wearing thin.