I think it is not Christmas they object to but to Santa Claus legend. Their objections merit that of some Christian parents. Such as upstaging Jesus. Having to lie and construct supporting lies to explain Santa. Encouraging a non spiritual/religious approach to Christmas.
The fact that Santa Claus originated with St. Nicholas is often lost on contemporary parents who have no idea of his Christian bona fides.
See no 'sarc' tag. So have to ask; you really believe this?
I look at Santa Claus as a metaphor for Jesus. Having Santa come down the chimley and bring presents and sweets for the children is a reminder of the Greater Gift that God made to us of his Only Begotten Son, Jesus Christ.