Post Request with null attribute

Hi,
We have below details in Section 7.9 POST (create) redfish specification

Services should return the HTTP 400 Bad Request status code for requests containing properties with the

value null .

As per schema we can have null value for some attributes and sending null value for that attribute in Post request won't be a problem.
I would like to know whether any specific purpose of returning HTTP 400 Bad Request status code for requests containing properties with the

value null . Is it ok to ignore the null value attribute and proceed with other attributes to complete post request?
Since specification mentioned as should return, it is recommended only and not mandatory to return  HTTP 400 Bad Request status code for requests containing properties with the value null .

Thanks,
Mani