Any reason to NOT use Postgres?

Hi, I'm looking to put in a new vSphere 6.5 environment,  less than 20 hosts and 200 VMs.  The vCenter has to be on windows. Is there any reason why I shouldn't use the inbuilt postgres DB?  Is it seen as a proper corporate fully supported solution? 

My other option is MS SQL but that will involved buying licences.

Thanks