I have a different question - which I recalled seeing the ridiculous precap of Rati cursing Parvati
Question is this - when Shiva was reminded after his marriage to provide the Devas w/ his son to lead them, he used some sparks to be given to Agni & Vayu, who took it to the Ganga, who took it to Shravan, and from where Kartikeya was born. Parvati was not 'needed' at all for Shiva to have his son.
So question is - why did the Devas have to wait for who knows how long for Mahadev to marry? Once Tarakasura had been given his boon, the Devas could have approached Mahadev for a son, and Mahadev could have done the same thing he did anyway - gotten the sparks, given them to Agni & Vayu and so on. Only that there would have been no Parvati to claim parentage, but Mahadev would have been available to take little Kartikeya, and raise him. Just cut the wait, and let Parvati get united w/ him whenever he felt like it (like he ultimately did), w/o delaying the destruction of Tarakasura.
And as for Ganesh later, since he was specifically created to obstruct Mahadev, I guess Parvati getting Mahadev to give her a son for that purpose would have been too ridiculous?
Anyway, particularly for my question about Kartikeya above - given what ultimately happened, why was it necessary for Mahadev to marry in order to give the Devas what they needed?
Oh, and an aside - was there any particular reason that Mahadev & Parvati didn't have any uterine babies?