Should Gossip Girl's Kelly Rutherford lose custody of her kids just because she is a working mom?

Kelly Rutherford’s husband is reportedly trying to get custody of the couple’s son Hermes. He reportedly claims he is better suited to be the custodial parent on account of the fact that Kelly just signed on with Gossip Girl for another year and so she will be working a lot. He feels that her job is incompatible with parenting Hermes and he feels that she is so busy that she loses patience with the child. Thus, he should get custody.
In New York, there is no presumption that the stay at home parent is more suitable to custody anymore. Traditionally wives have been stay at home moms and they have gotten custody. But the rules have been turned on their face. Now, many wives work outside the homes and in some cases, the husband is, gasp, a “house-husband.” But the courts have been unwilling to penalize the mother for working and so they won’t necessarily disrobe her of custody just because she works. That is why god created nannies, so that moms can work and still keep custody of the children, unless she is otherwise unfit.
I mean, if she can be shown to totally lack patience with the kids, and that she is never around to handle parenting duties and if the father is just more suited to custody and has been the main caregiver, she could lose custody. But she won’t lose it simply because she has a job. That’s ridiculous.