This is a good question. I believe that voyeurism, masochism and a submissive personality all are likely traits for a cuckold. One can be born with a predisposition for these things, but how a person turns out in life depends on upbringing and experience along with personality tendencies. A lot of posts in "how did you get started" cuckold threads are from men who were cuckolded in their teens/early twenties and found it to be a sexual turn-on. Usually these guys come across as being submissive and voyeuristic, and often masochistic as well. The experience of being cuckolded, along with one's personal inclinations, can combine to produce a sexual turn-on. Watching or letting "his" woman get fucked by another man, who is better endowed and more skilled than he is, just hurts so good. Others have not been cuckolded yet, but fantasize about it. For a white cuckold, seeing "his" white woman taken by a well-hung black stud makes the scene hotter by playing the race card.
When the woman is having sex with other men while her man remains faithful, there is a power differential in the relationship, with the woman having the upper hand. This is a D/s relationship which appeals to the cuckold's submissive nature. When another man with a longer and thicker cock enjoys filling her deeper and wider in places that the cuckold can never reach, and she obviously feels more pleasure being fucked by the other man, her cuckold feels a masochistic arousal, or is turned on because his wife is being fucked so well, or both.
There is one interesting side effect, experienced by many or most cuckolds, which appears to result from feelings of submission and masochism. It seems that a man who is being openly cuckolded by his wife or gf *usually* can not last nearly as long during sex with her as he did before the cuckolding started. Often he will shoot after two or three strokes, every time he fucks her. By finishing so quickly, he is ensuring that she gets most or all of her satisfaction from the other man. Usually he can't help it, and if she even mentions the other guy while he is inside her, he shoots immediately. His super quick orgasm seems to be caused by the excitement and intimidation of being a secondary, submissive lover to his cuckoldress, knowing that the other guy is fucking her and knowing that she loves it.
Of course there are exceptions. Most guys want to watch, but some would rather not. Some get a masochistic rush from being outperformed by the other man, while others are just happy that she is getting the good sex. For instance maybe she has a higher sex drive than her partner, who is both willing to share and motivated to see her sexually satisfied. There are all sorts of variations, but from what I have seen, more often than not a willing cuckold/wittol is sexually motivated by the things mentioned earlier. The short answer is that cuckolds are both born and made. They are born with likes/dislikes and with real (or imagined) physical shortcomings, *and* they are made by experience and conditioning. All in my opinion of course. Feedback about all of this would be appreciated.
